Article
Multidisciplinary Sciences
Chong Liu, Ryan P. Day, Fengmiao Li, Ryan L. Roemer, Sergey Zhdanovich, Sergey Gorovikov, Tor M. Pedersen, Juan Jiang, Sangjae Lee, Michael Schneider, Doug Wong, Pinder Dosanjh, Frederick J. Walker, Charles H. Ahn, Giorgio Levy, Andrea Damascelli, George A. Sawatzky, Ke Zou
Summary: The enhanced superconductivity in monolayer FeSe/SrTiO3 has been extensively studied over the past decade, with a focus on the replica bands in the photoemission spectrum. The authors conducted angle-resolved photoemission spectroscopy measurements and found unexpectedly high-intensity replica bands derived from various Fe 3d bands, providing new insights into the electronic structure and physical origin of the photoemission replica bands in this high-temperature superconductor.
NATURE COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
Jonathan Pelliciari, Seher Karakuzu, Qi Song, Riccardo Arpaia, Abhishek Nag, Matteo Rossi, Jiemin Li, Tianlun Yu, Xiaoyang Chen, Rui Peng, Mirian Garcia-Fernandez, Andrew C. Walters, Qisi Wang, Jun Zhao, Giacomo Ghiringhelli, Donglai Feng, Thomas A. Maier, Ke-Jin Zhou, Steven Johnston, Riccardo Comin
Summary: The study reveals a significant reconfiguration of spin excitations in FeSe/STO system compared to bulk FeSe, indicating a different behavior of spin excitations in the two systems.
NATURE COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
Liangzi Deng, Trevor Bontke, Rabin Dahal, Yu Xie, Bin Gao, Xue Li, Ketao Yin, Melissa Gooch, Donald Rolston, Tong Chen, Zheng Wu, Yanming Ma, Pengcheng Dai, Ching-Wu Chu
Summary: Raising the superconducting-transition temperature has been a key focus in superconductivity research. Recent advancements in hydrides have led to the possibility of room temperature superconductivity. New techniques may allow for maintaining high-temperature superconducting properties at ambient pressure.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Materials Science, Multidisciplinary
Qing Wang, Rui Song, Ning Hao
Summary: We propose the realization of a spin-dependent second-order topological insulator in a monolayer FeSe/GdClO heterostructure, with GdClO substrate enhancing the antiferromagnetic order. This topological insulator is not affected by spin-orbit coupling or in-plane magnetic field. The existence of distinct corner modes at the intersections of ferromagnetic and antiferromagnetic edges is observed, with the ferromagnetic corner modes following a sublattice-chirality-kink picture. Surprisingly, the antiferromagnetic corner modes can be understood as bound states of a one-dimensional Schrodinger equation with a connected potential well. This study not only presents a promising second-order topological insulator in electronic materials but also reveals unique properties of corner modes in high-order topological insulators.
Article
Materials Science, Multidisciplinary
Ji-hye Kim, Jong Mok Ok, Joonyoung Choi, Woun Kang, Jun Sung Kim, Younjung Jo
Summary: This paper investigates the relationship between the vortex pinning energy U-0/k(B) and the pressure-induced phases in FeSe single crystal. It is found that the dependence of U-0/k(B) on pressure at higher magnetic fields follows a similar trend as critical temperature T-c(p) and average Fermi velocity v over line (upsilon) over bar (F)(p). On the other hand, at lower magnetic fields, U-0/k(B) increases significantly before the occurrence of antiferromagnetic (AFM) long-range order, suggesting the presence of additional pinning sites possibly correlated with AFM domain boundaries. The paper also provides a universal description of the vortex dynamics in FeSe.
Article
Materials Science, Multidisciplinary
W. X. Wang, B. Lei, C. S. Zhu, J. H. Cui, W. Z. Zhuo, Z. J. Xiang, X. G. Luo, X. H. Chen
Summary: The electronic properties of FeSe thin flakes were successfully manipulated using a field-effect transistor with a solid proton conductor as the gate dielectric, showing three discrete superconducting phases. The study suggests that controlling the intercalated proton content can modulate physical properties and explore materials' hydrogen storage capacity.
Article
Materials Science, Multidisciplinary
Ivan Fotev, Stephan Winnerl, Saicharan Aswartham, Sabine Wurmehl, Bernd Buechner, Harald Schneider, Manfred Helm, Alexej Pashkin
Summary: In this study, the suppression of spin density wave (SDW) order in BaFe2As2 under pressure was investigated using optical pump-probe technique. The results show that the pressure-induced suppression of SDW order at low temperature occurs gradually, in contrast to the thermally induced SDW transition. This suggests that the pressure-driven quantum phase transition in BaFe2As2 (and probably other iron pnictides) is continuous and it is caused by the gradual worsening of the Fermi-surface nesting conditions.
Article
Materials Science, Multidisciplinary
H. Pfau, M. Yi, M. Hashimoto, T. Chen, P-C Dai, Z-X Shen, S-K Mo, D. Lu
Summary: The study investigates the influence of electronic nematicity on quasiparticle coherence in detwinned FeSe using ARPES, finding an anisotropy between dxz and dyz orbitals and a more coherent dxz orbital compared to the dyz orbital. This observation contrasts with earlier predictions and underscores the importance of electronic correlations in describing nematicity.
Article
Materials Science, Multidisciplinary
Yiqing Gu, Qisi Wang, Hongliang Wo, Zheng He, Helen C. Walker, Jitae T. Park, Mechthild Enderle, Andrew D. Christianson, Wenbin Wang, Jun Zhao
Summary: FeSe is a structurally simple high-temperature superconductor with an intriguing superconducting nematic paramagnetic phase and unusual spin excitation spectra. Neutron scattering measurements reveal highly frustrated nearest-neighbor and next-nearest-neighbor exchange couplings in FeSe, providing a natural explanation for its highly tunable superconductivity and nematicity.
Article
Materials Science, Multidisciplinary
Yan Meng, Xiangzhuo Xing, Xiaolei Yi, Bin Li, Nan Zhou, Meng Li, Yufeng Zhang, Wei Wei, Jiajia Feng, Kensei Terashima, Yoshihiko Takano, Yue Sun, Zhixiang Shi
Summary: In this paper, a series of discrete superconducting phases, with a maximum Tc up to 44 K, have been discovered in H+-intercalated FeSe single crystals using an ionic liquid gating method. With the increase of Tc, the nematic phase is suppressed and the transition from non-Fermi-liquid to Fermi-liquid behavior is observed. An abrupt change in the Fermi surface topology is proposed to explain the occurrence of these discrete superconducting phases.
Article
Materials Science, Multidisciplinary
Fengmiao Li, Ilya Elfimov, George A. Sawatzky
Summary: The discovery of higher-temperature superconductivity in FeSe monolayers on SrTiO3 substrates has sparked a surge of interest in interface superconductivity. The study finds that modulation doping by impurities in the substrate is critical for enhancing superconductivity, and there is likely an important interaction limiting the FeSe doping. Furthermore, the polarization change of the interface Se and the titanate substrate acting as a charge reservoir play important roles in the interface superconductivity.
Article
Physics, Applied
Sang Yong Song, Jungpil Seo
Summary: The response of non-magnetic impurities to superconductivity can help characterize the superconducting pairing symmetry, with s-wave superconductivity unaffected but unconventional superconductivity being affected by non-magnetic impurities. The study utilized scanning tunneling microscopy/spectroscopy to investigate the relevance of non-magnetic impurities to magnetism in FeSe, finding that these impurities and defects can induce local magnetism in the material.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Physical
Andrey V. Sadakov, Vladimir A. Vlasenko, Ivan A. Troyan, Oleg A. Sobolevskiy, Dmitrii V. Semenok, Di Zhou, Vladimir M. Pudalov
Summary: A comprehensive study was conducted on vortex phases and dynamics in the high-temperature superconductor YH(6) under a pressure of 200 GPa. The thermal activation energy and its dependence on magnetic field were analyzed using the thermally activated flux flow (TAFF) theory. The vortex phase transition from vortex glass to vortex liquid was studied, and a vortex phase diagram was constructed for superhydrides for the first time. The high flux flow barriers and crossover fields make YH6 an outstanding superconductor compared to other materials.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Materials Science, Multidisciplinary
S. Molatta, D. Opherden, J. Wosnitza, L. Opherden, Z. T. Zhang, T. Wolf, H. Loehneysen, R. Sarkar, P. K. Biswas, H-J Grafe, H. Kuehne
Summary: Recent experiments show that FeSe provides the possibility to study bulk superconductivity in the crossover regime between BCS and BEC. The research found a distinct state with large spin polarization in FeSe under strong magnetic fields along the c axis, indicating a high spatial homogeneity of the bulk superconducting state. Despite pronounced spin fluctuations, FeSe exhibits an unusual field-induced superconducting state in the BCS-BEC crossover regime.
Article
Materials Science, Multidisciplinary
Xuemin Fan, Wenqiang Cui, Yonghao Yuan, Qi-Kun Xue, Wei Li
Summary: In this study, the authors investigate the presence of the stripe phase in FeSe films on BaTiO3 and its correlation with interfacial superconductivity. They find that the stripe phase is more prominent in bilayer FeSe films and persists even at higher temperatures with alkali-metal deposition, indicating a strong correlation between the stripe phase and enhanced superconductivity.
Article
Chemistry, Multidisciplinary
Sang Yong Song, Chengyun Hua, Luke Bell, Wonhee Ko, Hans Fangohr, Jiaqiang Yan, Gabor B. Halasz, Eugene F. Dumitrescu, Benjamin J. Lawrie, Petro Maksymovych
Summary: New pathways are needed to control the morphology and dynamics of superconducting vortex lattices in order to transform them into a computing platform. It has been discovered that nematic twin boundaries can align superconducting vortices in adjacent terraces. Different structural phases of the vortex lattice can be assumed by varying the density and morphology of the twin boundaries. These findings have implications for the design and control of strain-based topological quantum computing architectures.
Article
Chemistry, Multidisciplinary
Martin Endres, Artem Kononov, Hasitha Suriya Arachchige, Jiaqiang Yan, David Mandrus, Kenji Watanabe, Takashi Taniguchi, Christian Schoenenberger
Summary: In this study, we measured a 4N-periodic switching current through an asymmetric SQUID formed by the higher-order topological insulator WTe2. We found that a high asymmetry in critical current and negligible loop inductance alone were not sufficient to reliably measure the current-phase relation. Instead, we discovered that our measurement was heavily influenced by additional inductances originating from the self-formed PdTex inside the junction. We developed a method to numerically recover the current-phase relation and found that the 1.5 μm long junction was best described in the short ballistic limit. Our results highlight the complexity of subtle inductance effects that can lead to misleading topological signatures in transport measurements.
Article
Multidisciplinary Sciences
Kohei Matsuura, Masaki Roppongi, Mingwei Qiu, Qi Sheng, Yipeng Cai, Kohtaro Yamakawa, Zurab Guguchia, Ryan P. Day, Kenji M. Kojima, Andrea Damascelli, Yuichi Sugimura, Mikihiko Saito, Takaaki Takenaka, Kota Ishihara, Yuta Mizukami, Kenichiro Hashimoto, Yilun Gu, Shengli Guo, Licheng Fu, Zheneng Zhang, Fanlong Ning, Guoqiang Zhao, Guangyang Dai, Changqing Jin, James W. Beare, Graeme M. Luke, Yasutomo J. Uemura, Takasada Shibauchi
Summary: Iron-chalcogenide superconductors FeSe1-xSx have unique electronic properties and the nature of superconductivity with nematicity is important for understanding unconventional superconductivity. Recent experiments show that the superconducting state in FeSe1-xSx breaks time-reversal symmetry and exhibits ultranodal pair state. The presence of broken TRS and suppressed superfluid density suggests the existence of two different superconducting states separated by the nematic critical point.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Multidisciplinary Sciences
M. Roppongi, K. Ishihara, Y. Tanaka, K. Ogawa, K. Okada, S. Liu, K. Mukasa, Y. Mizukami, Y. Uwatoko, R. Grasset, M. Konczykowski, B. R. Ortiz, S. D. Wilson, K. Hashimoto, T. Shibauchi
Summary: The recently discovered kagome superconductors AV(3)Sb(5) (A = K, Rb, Cs) exhibit unusual CDW orders with symmetry breaking. The symmetry of the superconductivity inside the CDW phase is still unknown. Impurity effects in CsV3Sb5 were studied using electron irradiation as a phase-sensitive probe, and the results indicate that CsV3Sb5 is a non-chiral, anisotropic s-wave superconductor with no sign change.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Kota Ishihara, Masaki Roppongi, Masayuki Kobayashi, Kumpei Imamura, Yuta Mizukami, Hironori Sakai, Petr Opletal, Yoshifumi Tokiwa, Yoshinori Haga, Kenichiro Hashimoto, Takasada Shibauchi
Summary: Evidence consistent with chiral B-3u+iA(u) spin-triplet superconductivity in UTe2 is found through magnetic penetration depth measurements.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Yoshito Watanabe, Atsushi Miyake, Masaki Gen, Yuta Mizukami, Kenichiro Hashimoto, Takasada Shibauchi, Akihiko Ikeda, Masashi Tokunaga, Takashi Kurumaji, Yusuke Tokunaga, Taka-hisa Arima
Summary: The magnetic phase diagram and double dome structure of a S = 3/2 quantum antiferromagnet is studied, with the importance of different types of magnetic Bose-Einstein condensates discussed. The effects of randomness induced by quenched disorder on the system are also investigated.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Tomoya Asaba, Lang Peng, Takahiro Ono, Satoru Akutagawa, Ibuki Tanaka, Hinako Murayama, Shota Suetsugu, Aleksandar Razpopov, Yuichi Kasahara, Takahito Terashima, Yuhki Kohsaka, Takasada Shibauchi, Masatoshi Ichikawa, Roser Valenti, Shin-ichi Sasa, Yuji Matsuda
Summary: We have discovered a simple method to fabricate atomic-scale wires with various arrangements, including stripes, X-junctions, Y-junctions, and nanorings. These wires are grown on graphite substrates by pulsed-laser deposition and have precise dimensions. Our findings suggest that nonequilibrium reaction-diffusion processes are crucial for the formation of atomic patterns, and this discovery opens up new possibilities for constructing quantum networks at the atomic scale.
Article
Materials Science, Multidisciplinary
Andrew F. May, Eleanor M. Clements, Heda Zhang, Raphael P. Hermann, Jiaqiang Yan, Michael A. McGuire
Summary: EuCuP and EuCuAs were studied to investigate their magnetic phase transitions and magnetoelastic coupling. EuCuP exhibited two closely spaced features in thermal expansion and specific heat capacity around the Curie temperature, possibly indicating a cascading magnetic transition or an electronic transition closely coupled to the magnetic ordering. Stronger zero-field magnetoelastic coupling was observed in EuCuP compared to EuCuAs, which was attributed to the dominant ferromagnetic interaction in EuCuP and antiferromagnetic order in EuCuAs. Anisotropic thermal expansion and strong ferromagnetic correlations were observed in EuCuAs above T-N. Both compounds showed similar electrical and thermoelectric transport behaviors, suggesting intrinsic defects and potential for achieving narrow-gap semiconducting or semimetallic behavior with defect tuning.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Michael A. McGuire, Heda Zhang, Andrew F. May, Satoshi Okamoto, Robert G. Moore, Xiaoping Wang, Clement Girod, Sean M. Thomas, Filip Ronning, Jiaqiang Yan
Summary: Alloying indium into SnBi2Te4 induces bulk superconductivity with critical temperatures up to 1.85 K and upper critical fields up to about 14 kOe. This is confirmed by electrical and thermal measurements, and the presence of a superconducting gap near 0.25 meV is suggested. The superconductivity is type-II and the existence of topological surface states has been verified. The analogy with MnBi2Te4 motivates further interest in this family of compounds, which have potential for the study of topological superconductivity.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Daniel J. Rizzo, Jin Zhang, Bjarke S. Jessen, Francesco L. Ruta, Matthew Cothrine, Jiaqiang Yan, David G. Mandrus, Stephen E. Nagler, Takashi Taniguchi, Kenji Watanabe, Michael M. Fogler, Abhay N. Pasupathy, Andrew J. Millis, Angel Rubio, James C. Hone, Cory R. Dean, D. N. Basov
Summary: The use of work-function-mediated charge transfer is explored for nanoscale electrostatic control of atomic layers. A thin layer of a-RuCl3 is found to induce emergent nano-optical behavior in hBN through interlayer charge polarization. The propagation length of hBN phonon polaritons is significantly reduced by the interfacial dipole formed by a-RuCl3, and a novel resonance is observed in nano-optical spectroscopy experiments. These findings demonstrate the potential of charge-transfer heterostructures for tailoring optoelectronic properties of 2D insulators.
Article
Chemistry, Multidisciplinary
Wonhee Ko, Sang Yong Song, Jiaqiang Yan, Jose L. Lado, Petro Maksymovych
Summary: This study introduces the unique capability of tunneling Andreev reflection (TAR) to probe unconventional pairing symmetry in low-dimensional unconventional superconductors. By studying the paradigmatic FeSe superconductor, we provide direct evidence of sign-changing order parameter, reveal the existence of two superconducting gaps, and confirm the local suppression of superconductivity along the nematic twin boundary. These findings enable new atomic-scale insight into microscopic, inhomogeneous, and interfacial properties of emerging quantum materials.
Article
Multidisciplinary Sciences
M. Culo, S. Licciardello, K. Ishida, K. Mukasa, J. Ayres, J. Buhot, Y. T. Hsu, S. Imajo, M. W. Qiu, M. Saito, Y. Uezono, T. Otsuka, T. Watanabe, K. Kindo, T. Shibauchi, S. Kasahara, Y. Matsuda, N. E. Hussey
Summary: The authors present high-field magnetotransport measurements of FeSe1-xSx and FeSe1-xTex, which show a broad quantum vortex liquid regime. This indicates the presence of a quantum vortex liquid state and the destruction of the Abrikosov lattice by intense quantum fluctuations at very low temperatures.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
P. F. Shanab, X. Han, X. Li, Z. Y. Liu, P. T. Yang, B. S. Wang, J. F. Wang, H. Y. Liu, Y. G. Shi, J. P. Sun, J. -g. Cheng
Summary: We successfully achieved the pressure-induced metallization of van der Waals cluster Mott insulator Nb3Cl8 through high-pressure measurements and calculations, and revealed the band-structure reconstruction and structural phase transition.
MATERIALS TODAY PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Lifen Shi, Binbin Ruan, Pengtao Yang, Ningning Wang, Pengfei Shan, Ziyi Liu, Jianping Sun, Yoshiya Uwatoko, Genfu Chen, Zhian Ren, Bosen Wang, Jinguang Cheng
Summary: We report the pressure-driven evolution of superconducting properties in the strong-coupling superconductor Ti4Ir2O. The superconducting transition temperature and upper critical field exhibit unusual behaviors under pressure, with a low pressure coefficient of Tc and a smooth crossover of Bc2 (0) beyond the Pauli paramagnetic limit. The findings provide insights into the resistance of this intriguing superconductor to external compression and strong magnetic fields.
Article
Materials Science, Multidisciplinary
Shunichiro Kittaka, Yohei Kono, Kaito Tsunashima, Daisuke Kimoto, Makoto Yokoyama, Yusei Shimizu, Toshiro Sakakibara, Minoru Yamashita, Kazushige Machida
Summary: The Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state in the superconductor CeCoIn5 is characterized by two anomalies in the magnetostriction along the c axis, parallel to the magnetic-field orientation, while no anomaly is observed along the a-axis direction. This uniaxial expansion could be attributed to the FFLO modulation vector parallel to the applied magnetic field.