Performance information

• Transverse Thermoelectric Conversion in the Mixed-Dimensional Semimetal WSi₂
  Shoya Ohsumi; Yoshiki J. Sato; Ryuji Okazaki
  PRX Energy, Volume：3, Number：4, Nov. 2024, [Reviewed]
  Materials with axis-dependent conduction polarity are known as p×n-type or goniopolar conductors that can be used for transverse thermoelectric devices, allowing the longitudinal thermal current to be converted into the transverse electrical current. Here, we have performed experimental and computational studies on the transport properties of WSi2 single crystals, in which such axis-dependent conduction polarity of the thermopower and the Hall coefficient have recently been reported, and demonstrated the transverse thermoelectric effect by applying the temperature gradient in a direction rotated 45∘ from the crystallographic axis. We have observed strongly sample-dependent transport properties, which have also been observed in previous studies, and together with first-principles calculations we show that such sample-dependent transport properties originate from the band-dependent scattering rates of carriers. The calculated band-resolved Peltier conductivity shows that the mixed-dimensional electronic structure consisting of a quasi-one-dimensional electron Fermi surface and a quasi-two-dimensional hole surface is a key property for the axis-dependent conduction polarity. The directly obtained transverse thermoelectric figure of merit is comparable to that of the anomalous Nernst materials, implying that the present material is a potential candidate for transverse thermoelectric conversion.
  
  Published by the American Physical Society 2024
  American Physical Society (APS), Scientific journal
  DOI：https://doi.org/10.1103/prxenergy.3.043007
  DOI ID：10.1103/prxenergy.3.043007, eISSN：2768-5608
• Low-temperature thermopower and phonon-drag effect in the quasi-one-dimensional cobaltate Ba₃Co₂O₆(CO₃)_0.7
  Asuka Komatsu; Yoshiki J. Sato; Shogo Yoshida; Ryuji Okazaki; Ryosuke Kurihara; Hiroshi Yaguchi
  Japanese Journal of Applied Physics, Volume：63, Number：11, First page：113001, Last page：113001, Nov. 2024, [Reviewed]
  Abstract
  
  The quasi-one-dimensional cobaltate Ba₃Co₂O₆(CO₃)_0.7 exhibits a high thermoelectric performance characterized by the large thermopower and high electrical conductivity above room temperature, while the low-temperature transport properties have been less investigated so far. Here, we systematically measure the thermopower of single-crystalline Ba₃Co₂O₆(CO₃)_0.7 samples at low temperatures. The temperature dependence of the thermopower near room temperature is similar to that of other thermoelectric cobaltates, such as layered cobaltates, but exhibits a sample-dependent prominent peak structure near T = 40 K. We evaluate the sample dependence of the carrier density and the mobility and find that the saturation effect of phonon drag is essential for the observed peak structure in the thermopower. The enhanced thermopower utilizing a phonon-drag effect in the present material may be crucial for low-temperature thermoelectrics.
  IOP Publishing, English, Scientific journal
  DOI：https://doi.org/10.35848/1347-4065/ad884e
  DOI ID：10.35848/1347-4065/ad884e, ISSN：0021-4922, eISSN：1347-4065
• Negatively enhanced thermopower near a Van Hove singularity in electron-doped Sr2RuO4
  Rei Nishinakayama; Yoshiki J. Sato; Takayoshi Yamanaka; Yoshiteru Maeno; Hiroshi Yaguchi; Naoki Kikugawa; Ryuji Okazaki
  Physical Review Research, Volume：6, Number：2, May 2024, [Reviewed]
  The layered perovskite Sr2RuO4 serves as a model material of the two-dimensional (2D) Fermi liquid but also exhibits various emergent phenomena including the non-Fermi-liquid (NFL) behavior under external perturbations such as uniaxial pressure and chemical substitutions. Here we present the thermoelectric transport of electron-doped system Sr2−yLayRuO4, in which a filling-induced Lifshitz transition occurs at the Van Hove singularity (VHS) point of y≈0.2. We find that the sign of the low-temperature thermopower becomes negative only near the VHS point, where the NFL behavior has been observed in the earlier study. This observation is incompatible with either a numerical calculation within a constant relaxation-time approximation or a toy-model calculation for the 2D Lifshitz transition adopting an elastic carrier scattering. As a promising origin of the observed negatively enhanced thermopower, we propose a skewed NFL state, in which an inelastic scattering with a considerable odd-frequency term plays a crucial role to negatively enhance the thermopower.
  
  Published by the American Physical Society 2024
  American Physical Society (APS), English, Scientific journal
  DOI：https://doi.org/10.1103/physrevresearch.6.023222
  DOI ID：10.1103/physrevresearch.6.023222, eISSN：2643-1564
• Thermoelectric transport properties of the quasi-one-dimensional dimer-Mott insulator β′-(BEDT-TTF)2ICl2
  Kyohei Eguchi; Takeru Ito; Yoshiki J. Sato; Ryuji Okazaki; Hiromi Taniguchi
  Physical Review Materials, Volume：8, Number：5, May 2024, [Reviewed]
  American Physical Society (APS), English, Scientific journal
  DOI：https://doi.org/10.1103/physrevmaterials.8.055402
  DOI ID：10.1103/physrevmaterials.8.055402, eISSN：2475-9953
• Large transverse thermoelectric effect induced by the mixed-dimensionality of Fermi surfaces
  Hikari Manako; Shoya Ohsumi; Yoshiki J. Sato; R. Okazaki; D. Aoki
  Nature Communications, Volume：15, Number：1, May 2024, [Reviewed], [Corresponding]
  Abstract
  
  Transverse thermoelectric effect, the conversion of longitudinal heat current into transverse electric current, or vice versa, offers a promising energy harvesting technology. Materials with axis-dependent conduction polarity, known as p × n-type conductors or goniopolar materials, are potential candidate, because the non-zero transverse elements of thermopower tensor appear under rotational operation, though the availability is highly limited. Here, we report that a ternary metal LaPt₂B with unique crystal structure exhibits axis-dependent thermopower polarity, which is driven by mixed-dimensional Fermi surfaces consisting of quasi-one-dimensional hole sheet with out-of-plane velocity and quasi-two-dimensional electron sheets with in-plane velocity. The ideal mixed-dimensional conductor LaPt₂B exhibits an extremely large transverse Peltier conductivity up to ∣α_yx∣ = 130 A K⁻¹ m⁻¹, and its transverse thermoelectric performance surpasses those of topological magnets utilizing the anomalous Nernst effect. These results thus manifest the mixed-dimensionality as a key property for efficient transverse thermoelectric conversion.
  Springer Science and Business Media LLC, English, Scientific journal
  DOI：https://doi.org/10.1038/s41467-024-48217-0
  DOI ID：10.1038/s41467-024-48217-0, eISSN：2041-1723
• Physical Properties of a New Ternary Compound RPt3Al5 (R = rare earth)　　　　　　　　　　　　　　　
  Hiroto Fukuda; Takatsugu Koizumi; Yoshiki J. Sato; Yusei Shimizu; Ai Nakamura; Dexin Li; Yoshiya Homma; Atsushi Miyake; Dai Aoki; Masashi Tokunaga; Ryoma Kato; Masanobu Shiga; Tatsuya Kawae; Fuminori Honda
  New Phys.: Sae Mulli, Volume：73, First page：1135, Last page：1139, Dec. 2023, [Reviewed]
  English, International conference proceedings
  DOI：https://doi.org/10.3938/NPSM.73.1135
  DOI ID：10.3938/NPSM.73.1135
• Carrier filtering effect for enhanced thermopower in a body-centered tetragonal ruthenate
  Ryota Otsuki; Yoshiki J. Sato; Ryuji Okazaki; Tomoya Komine; Ryosuke Kurihara; Hiroshi Yaguchi
  Physical Review Materials, Volume：7, Number：12, Dec. 2023, [Reviewed]
  American Physical Society (APS), English, Scientific journal
  DOI：https://doi.org/10.1103/physrevmaterials.7.125401
  DOI ID：10.1103/physrevmaterials.7.125401, eISSN：2475-9953
• Fermi surface topology and electronic transport properties of chiral crystal NbGe₂ with strong electron-phonon interaction
  Yoshiki J. Sato; Ai Nakamura; Rei Nishinakayama; Ryuji Okazaki; Hisatomo Harima; Dai Aoki
  Physical Review B, Volume：108, Number：23, Dec. 2023, [Reviewed], [Lead, Corresponding]
  American Physical Society (APS), English, Scientific journal
  DOI：https://doi.org/10.1103/physrevb.108.235115
  DOI ID：10.1103/physrevb.108.235115, ISSN：2469-9950, eISSN：2469-9969
• Impact of the Ce 4f states in the electronic structure of the intermediate-valence superconductor CeIr₃
  Shin-ichi Fujimori; Ikuto Kawasaki; Yukiharu Takeda; Hiroshi Yamagami; Norimasa Sasabe; Yoshiki J Sato; Ai Nakamura; Yusei Shimizu; Arvind Maurya; Yoshiya Homma; Dexin Li; Fuminori Honda; Dai Aoki
  Electronic Structure, Volume：5, Number：4, First page：045009, Last page：045009, Nov. 2023
  Abstract
  
  The electronic structure of the f-based superconductor $\mathrm{CeIr_3}$ was studied by photoelectron spectroscopy. The energy distribution of the $\mathrm{Ce}~4f$ states were revealed by the $\mathrm{Ce}~3d-4f$ resonant photoelectron spectroscopy. The $\mathrm{Ce}~4f$ states were mostly distributed in the vicinity of the Fermi energy, suggesting the itinerant character of the $\mathrm{Ce}~4f$ states. The contribution of the $\mathrm{Ce}~4f$ states to the density of states (DOS) at the Fermi energy was estimated to be nearly half of that of the $\mathrm{Ir}~5d$ states, implying that the $\mathrm{Ce}~4f$ states have a considerable contribution to the DOS at the Fermi energy. The $\mathrm{Ce}~3d$ core-level and $\mathrm{Ce}~3d$ x-ray absorption spectra were analyzed based on a single-impurity Anderson model. The number of the $\mathrm{Ce}~4f$ states in the ground state was estimated to be $0.8-0.9$, which is much larger than the values obtained in the previous studies (i.e. $0-0.4$).
  IOP Publishing, Scientific journal
  DOI：https://doi.org/10.1088/2516-1075/ad0a3d
  DOI ID：10.1088/2516-1075/ad0a3d, eISSN：2516-1075
• Mechanically exfoliated low-layered [Ca2CoO3]0.62[CoO2]: A single-crystalline p-type transparent conducting oxide
  Reiji Okada; Hiroto Isomura; Yoshiki J. Sato; Ryuji Okazaki; Masayuki Inoue; Shinya Yoshioka
  Applied Physics Letters, Volume：123, Number：5, Jul. 2023, [Reviewed]
  Transparent conducting oxides (TCOs) are essential components of optoelectronic devices and various materials have been explored for highly efficient TCOs having a combination of high transmittance and low sheet resistance. Here, we focus on a misfit thermoelectric oxide [Ca2CoO3]0.62[CoO2] and fabricate the transparent low-layered crystals by a mechanical tape-peeling method using the single-crystalline samples. From the transmittance measurement, we find that the thickness of low-layered samples is several orders of hundred nanometers, which is comparable with the estimation from the scanning electron microscopy images. Compared to the previous results on the polycrystalline and c-axis oriented transparent films, the electrical resistivity is reduced owing to the single-crystalline nature. The figure of merit for the transparent conducting materials in the present low-layered samples is then evaluated to be higher than the values in the previous reports. The present results on the low-layered single-crystalline [Ca2CoO3]0.62[CoO2] may offer a unique class of multi-functional transparent thermoelectric oxides.
  AIP Publishing, English, Scientific journal
  DOI：https://doi.org/10.1063/5.0162677
  DOI ID：10.1063/5.0162677, ISSN：0003-6951, eISSN：1077-3118
• Monoaxial Dzyaloshinskii-Moriya interaction–induced topological Hall effect in a new chiral-lattice magnet GdPt₂B
  Yoshiki J. Sato; Hikari Manako; Ryuji Okazaki; Yukio Yasui; Ai Nakamura; Dai Aoki
  Physical Review B, Volume：107, Number：21, Jun. 2023, [Reviewed], [Lead, Corresponding]
  American Physical Society (APS), English, Scientific journal
  DOI：https://doi.org/10.1103/physrevb.107.214420
  DOI ID：10.1103/physrevb.107.214420, ISSN：2469-9950, eISSN：2469-9969
• Superconductivity in Noncentrosymmetric LaNiZn Single Crystal
  Arvind Maurya; Hisatomo Harima; Fuminori Honda; Yusei Shimizu; Yoshiki J. Sato; Ai Nakamura; Dexin Li; Yoshiya Homma; Dai Aoki
  Journal of the Physical Society of Japan, Volume：92, Number：4, Apr. 2023
  Physical Society of Japan, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.92.043703
  DOI ID：10.7566/jpsj.92.043703, ISSN：0031-9015, eISSN：1347-4073
• Pressure-induced Structural Phase Transition and New Superconducting Phase in UTe₂
  Fuminori Honda; Shintaro Kobayashi; Naomi Kawamura; Saori I. Kawaguchi; Takatsugu Koizumi; Yoshiki J. Sato; Yoshiya Homma; Naoki Ishimatsu; Jun Gouchi; Yoshiya Uwatoko; Hisatomo Harima; Jacques Flouquet; Dai Aoki
  Journal of the Physical Society of Japan, Volume：92, Number：4, Apr. 2023
  Physical Society of Japan, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.92.044702
  DOI ID：10.7566/jpsj.92.044702, ISSN：0031-9015, eISSN：1347-4073
• Ising-type quasi-one-dimensional ferromagnetism with anisotropic hybridization in UNi4P2
  Arvind Maurya; Atsushi Miyake; Hisashi Kotegawa; Yusei Shimizu; Yoshiki J. Sato; Ai Nakamura; Dexin Li; Yoshiya Homma; Fuminori Honda; Masashi Tokunaga; Dai Aoki
  Physical Review B, Volume：107, Number：8, Feb. 2023
  American Physical Society (APS), Scientific journal
  DOI：https://doi.org/10.1103/physrevb.107.085142
  DOI ID：10.1103/physrevb.107.085142, ISSN：2469-9950, eISSN：2469-9969
• Anomalous electromagnetic response in the spin-triplet superconductor UTe2
  Yusei Shimizu; Shunichiro Kittaka; Yohei Kono; Toshiro Sakakibara; Kazushige Machida; Ai Nakamura; Dexin Li; Yoshiya Homma; Yoshiki J. Sato; Atsushi Miyake; Minoru Yamashita; Dai Aoki
  Physical Review B, Volume：106, Number：21, Dec. 2022
  American Physical Society (APS), Scientific journal
  DOI：https://doi.org/10.1103/physrevb.106.214525
  DOI ID：10.1103/physrevb.106.214525, ISSN：2469-9950, eISSN：2469-9969
• Single-Crystal Growth and Fermi Surface Properties of LaPd₂Si₂: Comparison with Pressure-Induced Heavy-Fermion Superconductor CePd₂Si₂
  Yoshiki J. Sato; Fuminori Honda; Jiří Pospíšil; Ai Nakamura; Michal Vališka; Yusei Shimizu; Arvind Maurya; Yoshiya Homma; Dexin Li; Vladimír Sechovský; Hisatomo Harima; Dai Aoki
  Journal of the Physical Society of Japan, Volume：91, Number：11, Nov. 2022, [Reviewed], [Lead, Corresponding]
  Physical Society of Japan, English, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.91.114708
  DOI ID：10.7566/jpsj.91.114708, ISSN：0031-9015, eISSN：1347-4073
• New Gd-based magnetic compound GdPt₂B with a chiral crystal structure
  Yoshiki J. Sato; Hikari Manako; Yoshiya Homma; Dexin Li; Ryuji Okazaki; Dai Aoki
  Physical Review Materials, Volume：6, Number：10, Oct. 2022, [Reviewed], [Lead, Corresponding]
  American Physical Society (APS), English, Scientific journal
  DOI：https://doi.org/10.1103/physrevmaterials.6.104412
  DOI ID：10.1103/physrevmaterials.6.104412, eISSN：2475-9953
• Anisotropic spin-glass and magnetic behavior in single-crystalline U2PtSi3　　　　　　　　　　　　　　　
  D.X. Li; Y. Shimizu; A. Nakamura; Y.J. Sato; Y. Homma; F. Honda; D. Aoki
  Journal of Magnetism and Magnetic Materials, Volume：562, First page：169820, Last page：169820, Aug. 2022, [Reviewed]
  Elsevier BV, English, Scientific journal
  DOI：https://doi.org/10.1016/j.jmmm.2022.169820
  DOI ID：10.1016/j.jmmm.2022.169820, ISSN：0304-8853
• Magnetovolume Effect on the First-Order Metamagnetic Transition in UTe2
  Atsushi Miyake; Masaki Gen; Akihiko Ikeda; Kazumasa Miyake; Yusei Shimizu; Yoshiki J. Sato; Dexin Li; Ai Nakamura; Yoshiya Homma; Fuminori Honda; Jacques Flouquet; Masashi Tokunaga; Dai Aoki
  Journal of the Physical Society of Japan, Volume：91, Number：6, Jun. 2022, [Reviewed]
  Physical Society of Japan, English, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.91.063703
  DOI ID：10.7566/jpsj.91.063703, ISSN：0031-9015, eISSN：1347-4073
• Abrupt Change in Electronic States under Pressure in New Compound EuPt₃Al₅　　　　　　　　　　　　　　　
  Takatsugu Koizumi; Fuminori Honda; Yoshiki J. Sato; Dexin Li; Dai Aoki; Yoshinori Haga; Jun Gouchi; Shoko Nagasaki; Yoshiya Uwatoko; Yoshio Kaneko; Yoshichika Ōnuki
  Journal of the Physical Society of Japan, Volume：91, Number：4, Apr. 2022, [Reviewed]
  We successfully grew single crystals of a new ternary Eu-divalent compound, EuPt3Al5, with an orthorhombic structure (Pnma, #62) using the Bridgman method. EuPt3Al5 orders antiferromagnetically below T-N = 12.4 K. T-N increases monotonically with increasing pressure up to 8.0 GPa, decreases slightly at 8.5 GPa, and suddenly becomes zero above 9.5 GPa. From the results of low-temperature dependences of electrical and residual resistivities, a sudden disappearance of the antiferromagnetic ordering occurs with a dramatic change in the Eu electronic states from the nearly divalent state to the valence fluctuating state at P-c approximate to 9 GPa. EuPt3Al5 is most likely the second material exhibiting an abrupt valence crossover in Eu compounds after EuCu2Ge2.
  Physical Society of Japan, English, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.91.043704
  DOI ID：10.7566/jpsj.91.043704, ISSN：0031-9015, eISSN：1347-4073, Web of Science ID：WOS:000785988000001
• Transition from spin glass to paramagnetism in the magnetic properties of PrAu₂Si₂
  D X Li; Y Shimizu; A Nakamura; Y J Sato; A Maurya; Y Homma; F Honda; D Aoki
  Journal of Physics: Condensed Matter, Volume：34, Number：13, First page：135805, Last page：135805, Mar. 2022, [Reviewed]
  Abstract
  
  It is unexpected that a spin-glass (SG) transition, which generally occurs only in systems with some form of disorder, was observed in the ThCr₂Si₂-type compound PrAu₂Si₂ at a temperature of ∼3 K. This puzzling phenomenon was later explained based on a novel dynamic frustration model that does not involve static disorder. We present the results of re-verification of the reported SG behaviors by measuring the physical properties of three polycrystalline PrAu₂Si₂ samples annealed under different conditions. Indeed, in the sample annealed at 827 °C for one week, a SG transition does occur at a temperature of T_f ∼ 2.8 K as that reported previously in the literature. However, it is newly found that the SG effect is actually more pronounced in the as-cast sample, and almost completely disappears in the well-annealed (at 850 °C for four weeks) sample. The annealing effect observed in PrAu₂Si₂, that is, SG to paramagnetism transition is discussed by comparing with earlier results reported on the same system and other isomorphic compounds.
  IOP Publishing, English, Scientific journal
  DOI：https://doi.org/10.1088/1361-648x/ac49c7
  DOI ID：10.1088/1361-648x/ac49c7, ISSN：0953-8984, eISSN：1361-648X
• Pressure-induced multicriticality and electronic instability in the quasi-kagome ferromagnet URhSn　　　　　　　　　　　　　　　
  Arvind Maurya; Dilip Bhoi; Fuminori Honda; Yusei Shimizu; Ai Nakamura; Yoshiki J. Sato; Dexin Li; Yoshiya Homma; M. Sathiskumar; Jun Gouchi; Yoshiya Uwatoko; Dai Aoki
  Physical Review B, Volume：104, Number：19, Nov. 2021, [Reviewed]
  We report an unconventional class of pressure-induced quantum phase transitions, possessing two bicritical points at 6.25 GPa in URhSn. This unique transformation accompanies a Fermi surface reconstruction, demarcating competing ordered phases suitably described with a localized and itinerant description of the magnetic 5 f electrons. Ferromagnetic fluctuations over a wide range of temperatures and pressures in the pressure-induced low temperature phase are evidenced by a robust T 5/3 temperature dependence of resistivity up to 11 GPa, which is a characteristic of an elusive marginal Fermi-liquid state.
  American Physical Society (APS), English, Scientific journal
  DOI：https://doi.org/10.1103/physrevb.104.195119
  DOI ID：10.1103/physrevb.104.195119, ISSN：2469-9950, eISSN：2469-9969, Web of Science ID：WOS:000718585400001
• Enhancement and Discontinuity of Effective Mass through the First-Order Metamagnetic Transition in UTe₂　　　　　　　　　　　　　　　
  Atsushi Miyake; Yusei Shimizu; Yoshiki J. Sato; Dexin Li; Ai Nakamura; Yoshiya Homma; Fuminori Honda; Jacques Flouquet; Masashi Tokunaga; Dai Aoki
  Journal of the Physical Society of Japan, Volume：90, Number：10, First page：103702, Last page：103702, Oct. 2021, [Reviewed]
  In this study, the metamagnetic transitions in the novel spin-triplet superconductor UTe2 are investigated based on the recently developed simultaneous measurements of magnetization and sample temperature for the applied field along the orthorhombic b-axis and close to the [011] direction, where reentrant superconductivity (RSC) is detected below and above the first-order metamagnetic transition field H-m. Combining Maxwell's relation and the Clausius-Clapeyron equation, we obtain the field dependence of the Sommerfeld coefficient gamma through the first-order metamagnetic transition. A significant enhancement in the effective mass toward Hm is detected in both field directions. In contrast, above Hm, the effective mass discontinuously decreases for H parallel to b, while it discontinuously increases for H parallel to similar to[011], which plays a crucial role in the RSC.
  Physical Society of Japan, English, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.90.103702
  DOI ID：10.7566/jpsj.90.103702, ISSN：0031-9015, eISSN：1347-4073, Web of Science ID：WOS:000704344000005
• Magnetic Properties under Pressure in Novel Spin-Triplet Superconductor UTe₂　　　　　　　　　　　　　　　
  Dexin Li; Ai Nakamura; Fuminori Honda; Yoshiki J. Sato; Yoshiya Homma; Yusei Shimizu; Jun Ishizuka; Youichi Yanase; Georg Knebel; Jacques Flouquet; Dai Aoki
  Journal of the Physical Society of Japan, Volume：90, Number：7, First page：073703, Last page：073703, Jul. 2021, [Reviewed]
  We report the magnetic susceptibility and the magnetization under pressures up to 1.7 GPa above the critical pressure, P-c similar to 1.5 GPa, for H parallel to a, b, and c-axes in the novel spin triplet superconductor UTe2. The anisotropic magnetic susceptibility at low pressure with the easy magnetization a-axis changes to the quasi-isotropic behavior at high pressure, revealing a rapid suppression of the susceptibility for a-axis, and a gradual increase of the susceptibility for the b-axis. At 1.7 GPa above P-c, magnetic anomalies are detected at T-MO similar to 3K and T-WMO similar to 10 K. The former anomaly corresponds to long-range magnetic order, most likely antiferromagnetism, while the latter shows a broad anomaly, which is probably due to the development of short range order. The unusual decrease and increase of the susceptibility below T-WMO for H parallel to a and b-axes, respectively, indicate the complex magnetic properties at low temperatures above P-c. This is related to the interplay between multiple fluctuations dominated by antiferromagnetism, ferromagnetism, valence and Fermi surface instabilities.
  Physical Society of Japan, English, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.90.073703
  DOI ID：10.7566/jpsj.90.073703, ISSN：0031-9015, eISSN：1347-4073, Web of Science ID：WOS:000669534200005
• Field-Induced Superconductivity near the Superconducting Critical Pressure in UTe2　　　　　　　　　　　　　　　
  Dai Aoki; Motoi Kimata; Yoshiki J. Sato; Georg Knebel; Fuminori Honda; Ai Nakamura; Dexin Li; Yoshiya Homma; Yusei Shimizu; William Knafo; Daniel Braithwaite; Michal Vališka; Alexandre Pourret; Jean-Pascal Brison; Jacques Flouquet
  Journal of the Physical Society of Japan, Volume：90, Number：7, First page：074705, Last page：074705, Jul. 2021, [Reviewed]
  We report the magnetoresistance under pressure in the novel spin-triplet superconductor UTe2 close to the critical pressure P-c, where the superconducting phase terminates, for field along the three a, b, and c-axes in the orthorhombic structure. The superconducting phase for H parallel to a-axis just below P-c shows a field-reentrant behavior due to the competition with the emergence of magnetic order at low fields. The upper critical field H-c2 for H parallel to c-axis shows a quasi-vertical increase in the H-T phase diagram just below P-c, indicating that superconductivity is reinforced by the strong fluctuations which persist even at high fields above 20 T. Increasing pressure leads to the disappearance of superconductivity at zero field with the emergence of magnetic order. Surprisingly, field-induced superconductivity is observed at high fields, where a spin-polarized state is realized due to the suppression of the magnetic ordered phases; the spin-polarized state is favorable for superconductivity, whereas the magnetic ordered phase at low field seems to be unfavorable. The huge H-c2 in the spin-polarized state seems to imply a spin-triplet state. Contrary to the a- and c-axes, no field-reinforcement of superconductivity occurs for magnetic field along the b-axis. We compare the results with the field-reentrant superconductivity above the metamagnetic field, H-m for the field direction tilted by similar to 30 deg from b to c-axis at ambient pressure as well as the field-reentrant (-reinforced) superconductivity in ferromagnetic superconductors, URhGe and UCoGe.
  Physical Society of Japan, English, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.90.074705
  DOI ID：10.7566/jpsj.90.074705, ISSN：0031-9015, eISSN：1347-4073, Web of Science ID：WOS:000669534200021
• Pairing symmetry of an intermediate valence superconductor CeIr3 investigated using μSR measurements
  D. T. Adroja; A. Bhattacharyya; Y. J. Sato; M. R. Lees; P. K. Biswas; K. Panda; V. K. Anand; Gavin B. G. Stenning; A. D. Hillier; D. Aoki
  Physical Review B, Volume：103, Number：10, Mar. 2021, [Reviewed]
  American Physical Society (APS), English, Scientific journal
  DOI：https://doi.org/10.1103/physrevb.103.104514
  DOI ID：10.1103/physrevb.103.104514, ISSN：2469-9950, eISSN：2469-9969
• Single-crystal growth and magnetic phase diagram of the enantiopure crystal of NdPt₂B　　　　　　　　　　　　　　　
  Yoshiki J. Sato; Fuminori Honda; Arvind Maurya; Yusei Shimizu; Ai Nakamura; Yoshiya Homma; Dexin Li; Yoshinori Haga; Dai Aoki
  Physical Review Materials, Volume：5, Number：3, Mar. 2021, [Reviewed], [Lead, Corresponding]
  We report on the enantiopure single-crystal growth using the Czochralski method and the magnetic properties of the Nd-based monoaxial chiral magnet NdPt2B based on electrical resistivity, specific heat, and magnetization measurements. A peak in the magnetic susceptibility and a lambda-type anomaly in the specific heat are observed at T-N1 = 19.5 K. Successively, a first-order magnetic transition at T-m = 9.5 K is observed in the electrical resistivity, specific heat, and magnetic susceptibility. In addition, we observed a new magnetic phase transition, which has previously not been reported, at T-N2 = 11 K between T-N1 and T-m. We observed multiple plateaus in the low-temperature magnetic phase and constructed a nontrivial magnetic phase diagram, which results from the competitive interactions in this system. Furthermore, we observed an increase and decrease in the in-plane anisotropy in the transverse magnetoresistance, which is related to the change in the magnetic structure.
  American Physical Society (APS), English, Scientific journal
  DOI：https://doi.org/10.1103/physrevmaterials.5.034411
  DOI ID：10.1103/physrevmaterials.5.034411, ISSN：2475-9953, eISSN：2475-9953, Web of Science ID：WOS:000655910400004
• Two-gap time reversal symmetry breaking superconductivity in noncentrosymmetric LaNiC2
  Shyam Sundar; S. R. Dunsiger; S. Gheidi; K. S. Akella; A. M. Côté; H. U. Özdemir; N. R. Lee-Hone; D. M. Broun; E. Mun; F. Honda; Y. J. Sato; T. Koizumi; R. Settai; Y. Hirose; I. Bonalde; J. E. Sonier
  Physical Review B, Volume：103, Number：1, Jan. 2021, [Reviewed]
  American Physical Society (APS), English, Scientific journal
  DOI：https://doi.org/10.1103/physrevb.103.014511
  DOI ID：10.1103/physrevb.103.014511, ISSN：2469-9950, eISSN：2469-9969
• Anisotropy of upper critical field and surface superconducting state in the intermediate-valence superconductor CeIr₃
  Yoshiki J. Sato; Fuminori Honda; Yusei Shimizu; Ai Nakamura; Yoshiya Homma; Arvind Maurya; Dexin Li; Takatsugu Koizumi; Dai Aoki
  Physical Review B, Volume：102, Number：17, Nov. 2020, [Reviewed], [Lead, Corresponding]
  American Physical Society (APS), English, Scientific journal
  DOI：https://doi.org/10.1103/physrevb.102.174503
  DOI ID：10.1103/physrevb.102.174503, ISSN：2469-9950, eISSN：2469-9969
• Strong magnetic anisotropy and unusual magnetic field reinforced phase in URhSn with a quasi-kagome structure
  Yusei Shimizu; Atsushi Miyake; Arvind Maurya; Fuminori Honda; Ai Nakamura; Yoshiki J. Sato; Dexin Li; Yoshiya Homma; Makoto Yokoyama; Yo Tokunaga; Masashi Tokunaga; Dai Aoki
  Physical Review B, Volume：102, Number：13, Oct. 2020, [Reviewed]
  American Physical Society (APS), English, Scientific journal
  DOI：https://doi.org/10.1103/physrevb.102.134411
  DOI ID：10.1103/physrevb.102.134411, ISSN：2469-9950, eISSN：2469-9969
• Magnetic and transport properties of new ternary uranium-based germanide U₂Rh₃Ge₅
  D X Li; Y Shimizu; A Nakamura; A Maurya; Y J Sato; Y Homma; F Honda; D Aoki
  Journal of Physics: Condensed Matter, Volume：32, Number：49, First page：495804, Last page：495804, Sep. 2020, [Reviewed]
  Abstract
  
  A new ternary uranium germanide U₂Rh₃Ge₅ has been successfully synthesized and investigated by means of magnetic susceptibility χ(T, H), isothermal magnetization M(T, H), electrical resistivity ρ(T), and specific heat C(T, H) measurements. This compound is found to crystallize in the U₂Co₃Si₅-type orthorhombic structure. The low-field χ(T) shows a clear peak at T_N = 41.5 K corresponding to an antiferromagnetic transition. The M(H) curve measured up to 70 kOe exhibits an H-linear behavior at 2 K with very small induced magnetic moments, while it shows upward curvature with increasing temperature, implying the possible presence of a metamagnetic transition in high-field region above 70 kOe. As the temperature decreases, ρ(T) increases slowly at T > T_N and decreases rapidly at T < T_N, which can be understood based on a semiconductor-like narrow band gap model (or the c-f hybridization effect) and an antiferromagnetic spin-wave model, respectively. No evidence of heavy-fermion behavior or superconductivity transition is observed at temperatures as low as 0.4 K. The obtained experimental results are discussed by comparing with those reported for the isomorphic compound U₂Ir₃Si₅ and the quasi-isomorphic compound U₂Rh₃Si₅.
  IOP Publishing, English, Scientific journal
  DOI：https://doi.org/10.1088/1361-648x/abb31a
  DOI ID：10.1088/1361-648x/abb31a, ISSN：0953-8984, eISSN：1361-648X
• de Haas–van Alphen Effect and Fermi Surface Properties in Single-Crystalline ThCu₂Si₂
  Ai Nakamura; Fuminori Honda; Yoshiya Homma; Dexin Li; Yusei Shimizu; Arvind Maurya; Yoshiki J. Sato; Hisatomo Harima; Yoshichika Ōnuki; Dai Aoki
  Journal of the Physical Society of Japan, Volume：89, Number：9, First page：094703, Last page：094703, Sep. 2020, [Reviewed]
  Physical Society of Japan, English, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.89.094703
  DOI ID：10.7566/jpsj.89.094703, ISSN：0031-9015, eISSN：1347-4073
• Orbital crossing in spin-split Fermi surfaces and anisotropic effective mass of the noncentrosymmetric heavy-fermion paramagnet UPt₅
  Yoshiki J. Sato; Hisatomo Harima; Ai Nakamura; Arvind Maurya; Yusei Shimizu; Yoshiya Homma; Dexin Li; Fuminori Honda; Dai Aoki
  Physical Review B, Volume：102, Number：12, Sep. 2020, [Reviewed], [Lead, Corresponding]
  American Physical Society (APS), English, Scientific journal
  DOI：https://doi.org/10.1103/physrevb.102.125114
  DOI ID：10.1103/physrevb.102.125114, ISSN：2469-9950, eISSN：2469-9969
• Anisotropy of the Upper Critical Field in the Heavy-Fermion Superconductor UTe₂ under Pressure
  Georg Knebel; Motoi Kimata; Michal Vališka; Fuminori Honda; DeXin Li; Daniel Braithwaite; Gérard Lapertot; William Knafo; Alexandre Pourret; Yoshiki J. Sato; Yusei Shimizu; Takumi Kihara; Jean-Pascal Brison; Jacques Flouquet; Dai Aoki
  Journal of the Physical Society of Japan, Volume：89, Number：5, First page：053707, Last page：053707, May 2020, [Reviewed]
  Physical Society of Japan, English, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.89.053707
  DOI ID：10.7566/jpsj.89.053707, ISSN：0031-9015, eISSN：1347-4073
• Multiple Superconducting Phases and Unusual Enhancement of the Upper Critical Field in UTe₂
  Dai Aoki; Fuminori Honda; Georg Knebel; Daniel Braithwaite; Ai Nakamura; DeXin Li; Yoshiya Homma; Yusei Shimizu; Yoshiki J. Sato; Jean-Pascal Brison; Jacques Flouquet
  Journal of the Physical Society of Japan, Volume：89, Number：5, First page：053705, Last page：053705, May 2020, [Reviewed]
  Physical Society of Japan, English, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.89.053705
  DOI ID：10.7566/jpsj.89.053705, ISSN：0031-9015, eISSN：1347-4073
• Spin-Triplet Superconductivity in UTe₂ and Ferromagnetic Superconductors
  Dai Aoki; Ai Nakamura; Fuminori Honda; DeXin Li; Yoshiya Homma; Yusei Shimizu; Yoshiki J. Sato; Georg Knebel; Jean-Pascal Brison; Alexandre Pourret; Daniel Braithwaite; Gerard Lapertot; Qun Niu; Michal Vališka; Hisatomo Harima; Jacques Flouquet
  Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2019), Mar. 2020, [Reviewed]
  Journal of the Physical Society of Japan, English, International conference proceedings
  DOI：https://doi.org/10.7566/jpscp.30.011065
  DOI ID：10.7566/jpscp.30.011065
• Single Crystal Growth and de Haas–van Alphen Effect of Non-Centrosymmetric Heavy-Fermion Compound UPt₅
  Yoshiki J. Sato; Hisatomo Harima; Ai Nakamura; Arvind Maurya; Yusei Shimizu; Yoshiya Homma; Dexin Li; Fuminori Honda; Dai Aoki
  Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2019), Mar. 2020, [Lead, Corresponding]
  Journal of the Physical Society of Japan, English, International conference proceedings
  DOI：https://doi.org/10.7566/jpscp.30.011171
  DOI ID：10.7566/jpscp.30.011171
• Magnetic and Electronic Properties of the Ternary Compound U2T3Si5 (T = Rh, Ir)
  Fuminori Honda; Naomi Kawamura; Dexin Li; Yusuke Hirose; Yoshiya Homma; Ai Nakamura; Yusei Shimizu; Arvind Maurya; Yoshiki J. Sato; Dai Aoki
  Proceedings of J-Physics 2019: International Conference on Multipole Physics and Related Phenomena, Feb. 2020, [Reviewed]
  Journal of the Physical Society of Japan, English, International conference proceedings
  DOI：https://doi.org/10.7566/jpscp.29.013002
  DOI ID：10.7566/jpscp.29.013002
• Electrical Transport under Pressure in Non-centrosymmetric URhSn
  Arvind Maurya; Fuminori Honda; Yusei Shimizu; Ai Nakamura; Yoshiki J. Sato; Yoshiya Homma; DeXin Li; Dai Aoki
  Proceedings of J-Physics 2019: International Conference on Multipole Physics and Related Phenomena, Feb. 2020, [Reviewed]
  Journal of the Physical Society of Japan, English, International conference proceedings
  DOI：https://doi.org/10.7566/jpscp.29.014003
  DOI ID：10.7566/jpscp.29.014003
• Single Crystal Growth and Anisotropy of the Upper Critical Field of CeIr3
  Yoshiki J. Sato; Yusei Shimizu; Fuminori Honda; Ai Nakamura; Yoshiya Homma; Arvind Maurya; Dexin Li; Dai Aoki
  Proceedings of J-Physics 2019: International Conference on Multipole Physics and Related Phenomena, Feb. 2020, [Reviewed], [Lead, Corresponding]
  Journal of the Physical Society of Japan, English, International conference proceedings
  DOI：https://doi.org/10.7566/jpscp.29.011007
  DOI ID：10.7566/jpscp.29.011007
• Ir 5d-band derived superconductivity in LaIr3
  A Bhattacharyya; D T Adroja; P K Biswas; Y J Sato; M R Lees; D Aoki; A D Hillier
  Journal of Physics: Condensed Matter, Volume：32, Number：6, First page：065602, Last page：065602, Feb. 2020, [Reviewed]
  IOP Publishing, English, Scientific journal
  DOI：https://doi.org/10.1088/1361-648x/ab4389
  DOI ID：10.1088/1361-648x/ab4389, ISSN：0953-8984, eISSN：1361-648X
• Magnetic Fluctuation and First-Order Transition in Trillium Lattice of EuPtSi Observed by 151Eu Mössbauer Spectroscopy
  Yoshiya Homma; Masashi Kakihana; Yo Tokunaga; Mamoru Yogi; Miho Nakashima; Ai Nakamura; Yusei Shimizu; Dexin Li; Arvind Maurya; Yoshiki J. Sato; Fuminori Honda; Dai Aoki; Yasushi Amako; Masato Hedo; Takao Nakama; Yoshichika Ōnuki
  Journal of the Physical Society of Japan, Volume：88, Number：9, First page：094702, Last page：094702, Sep. 2019, [Reviewed]
  Japan Society of Applied Physics, English, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.88.094702
  DOI ID：10.7566/jpsj.88.094702, ISSN：0031-9015, eISSN：1347-4073
• Metamagnetic Transition in Heavy Fermion Superconductor UTe₂
  Atsushi Miyake; Yusei Shimizu; Yoshiki J. Sato; Dexin Li; Ai Nakamura; Yoshiya Homma; Fuminori Honda; Jacques Flouquet; Masashi Tokunaga; Dai Aoki
  Journal of the Physical Society of Japan, Volume：88, Number：6, First page：063706, Last page：063706, Jun. 2019, [Reviewed]
  Physical Society of Japan, English, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.88.063706
  DOI ID：10.7566/jpsj.88.063706, ISSN：0031-9015, eISSN：1347-4073
• Unconventional Superconductivity in Heavy Fermion UTe2
  Dai Aoki; Ai Nakamura; Fuminori Honda; DeXin Li; Yoshiya Homma; Yusei Shimizu; Yoshiki J. Sato; Georg Knebel; Jean-Pascal Brison; Alexandre Pourret; Daniel Braithwaite; Gerard Lapertot; Qun Niu; Michal Vališka; Hisatomo Harima; Jacques Flouquet
  Journal of the Physical Society of Japan, Volume：88, Number：4, First page：043702, Last page：043702, Apr. 2019, [Reviewed]
  Japan Society of Applied Physics, English, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.88.043702
  DOI ID：10.7566/jpsj.88.043702, ISSN：0031-9015, eISSN：1347-4073
• Magnetic and electrical properties of the ternary compound U2Ir3Si5 with one-dimensional uranium zigzag chains
  D. X. Li; F. Honda; A. Miyake; Y. Homma; Y. Haga; A. Nakamura; Y. Shimizu; A. Maurya; Y. J. Sato; M. Tokunaga; D. Aoki
  Physical Review B, Volume：99, Number：5, Feb. 2019, [Reviewed]
  American Physical Society (APS), English, Scientific journal
  DOI：https://doi.org/10.1103/physrevb.99.054408
  DOI ID：10.1103/physrevb.99.054408, ISSN：2469-9950, eISSN：2469-9969
• Magnetic Properties of Heavy Fermion Compound Ce₅Si₄ with Chiral Structure
  Yoshiki J. Sato; Yusei Shimizu; Ai Nakamura; Yoshiya Homma; Dexin Li; Arvind Maurya; Fuminori Honda; Dai Aoki
  Journal of the Physical Society of Japan, Volume：87, Number：7, First page：074701, Last page：074701, Jul. 2018, [Reviewed], [Lead, Corresponding]
  Japan Society of Applied Physics, English, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.87.074701
  DOI ID：10.7566/jpsj.87.074701, ISSN：0031-9015, eISSN：1347-4073
• Superconducting Properties of CeIr₃ Single Crystal
  Yoshiki J. Sato; Ai Nakamura; Yusei Shimizu; Arvind Maurya; Yoshiya Homma; Dexin Li; Fuminori Honda; Dai Aoki
  Journal of the Physical Society of Japan, Volume：87, Number：5, First page：053704, Last page：053704, May 2018, [Reviewed], [Lead, Corresponding]
  Japan Society of Applied Physics, English, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.87.053704
  DOI ID：10.7566/jpsj.87.053704, ISSN：0031-9015, eISSN：1347-4073
• Pressure-induced valence change and moderate heavy fermion state in Eu-compounds　　　　　　　　　　　　　　　
  Fuminori Honda; Keigo Okauchi; Yoshiki Sato; Ai Nakamura; Hiromu Akamine; Yosuke Ashitomi; Masato Hedo; Takao Nakama; Tetsuya Takeuchi; Jaroslav Valenta; Jiri Prchal; Vladimir Sechovský; Dai Aoki; Yoshichika Ōnuki
  Physica B: Condensed Matter, Volume：536, First page：182, Last page：191, May 2018, [Reviewed]
  A pressure-induced valence transition has attracted much attention in Eu-compounds. Among them, EuRh2Si2, EuNi2Ge2, and EuCo2Ge2 reveal the valence transition around 1, 2, and 3 GPa, respectively. We have succeeded in growing single crystals of EuT2X2 (T: transition metal, X: Si, Ge) and studied electronic properties under pressure. EuRh2Si2 indicates a first-order valence transition between 1 and 2 GPa, with a large and prominent hysteresis in the electrical resistivity. At higher pressures, the first-order valence transition changes to a crossover regime with an intermediate valence state. Tuning of the valence state with pressure is reflected in a drastic change of the temperature dependence of the electrical resistivity in EuRh2Si2 single crystals. Effect of pressure on the valence states on EuRh2Si2, EuIr2Si2, EuNi2Ge2, and EuCo2Ge2, as well as an isostructural related compound EuGa4, are reviewed.
  Elsevier BV, English, Scientific journal
  DOI：https://doi.org/10.1016/j.physb.2017.09.094
  DOI ID：10.1016/j.physb.2017.09.094, ISSN：0921-4526, eISSN：1873-2135, Web of Science ID：WOS:000431075600045
• Splitting Fermi Surfaces and Heavy Electronic States in Non-Centrosymmetric U3Ni3Sn4
  Arvind Maurya; Hisatomo Harima; Ai Nakamura; Yusei Shimizu; Yoshiya Homma; DeXin Li; Fuminori Honda; Yoshiki J. Sato; Dai Aoki
  Journal of the Physical Society of Japan, Volume：87, Number：4, First page：044703, Last page：044703, Apr. 2018, [Reviewed]
  Physical Society of Japan, English, Scientific journal
  DOI：https://doi.org/10.7566/jpsj.87.044703
  DOI ID：10.7566/jpsj.87.044703, ISSN：0031-9015, eISSN：1347-4073

• 電子状態の混合次元性を利用した巨大な横型熱電変換　　　　　　　　　　　　　　　
  眞子日佳里; 佐藤芳樹; 岡崎竜二
  First page：33, Last page：38, Oct. 2024, [Invited]
  English, Introduction commerce magazine

• Sep. 2022 - Present
  電磁気学演習
• Apr. 2022 - Present
  力学演習, Tokyo University of Science
• Apr. 2022 - Present
  基礎数学演習, Tokyo University of Science
• Apr. 2022
  物理学実験, Tokyo University of Science

• Apr. 2017 - Present