Article
Physics, Applied
L. M. B. Vargas, K. Bolanos, M. J. da Silva, S. de Castro, M. L. Peres, M. P. F. de Godoy
Summary: We systematically investigated the morphology and magnetotransport properties of Zn1-xCdxO/CdO heterostructures by changing the x values between 0.50 and 0.95. The disorder degree was found to be correlated with the amplitude of the negative magnetoresistance and the dominant inelastic scattering mechanisms. All heterostructures showed a negative amplitude in magnetoresistance measurements, indicating the presence of weak localization effect at low temperatures. Using the three-dimensional weak localization theory (Kawabata 3D), we determined a relatively large phase coherence length (up to 135 nm at 4.2 K) for the Zn0.05Cd0.95O/CdO heterostructure.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Lucia Varbaro, Bernat Mundet, Claribel Dominguez, Jennifer Fowlie, Alexandru B. Georgescu, Lukas Korosec, Duncan T. L. Alexander, Jean-Marc Triscone
Summary: In rare earth nickelates, the metal-to-insulator transition can be explained by an electronic and structural order parameter. The coupling of metal-to-insulator transitions observed at the SmNiO3/NdNiO3 interface is studied using SmNiO3/NdNiO3 superlattices with insulating LaAlO3 spacer layers, revealing that the electronic order parameter is responsible for the coupling. The complete decoupling of the metal-to-insulator transitions by inserting a single unit cell of LaAlO3 between SmNiO3 and NdNiO3 suggests the dominance of the electronic order parameter in controlling the coupling.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Physics, Multidisciplinary
Wen-Hao Liu, Yu-Xiang Gu, Zhi Wang, Shu-Shen Li, Lin -Wang Wang, Jun-Wei Luo
Summary: In contrast to conventional charge density wave (CDW) materials, the one-dimensional CDW on the In/Si(111) surface quickly dampens during the photoinduced phase transition. By using real-time time-dependent density functional theory (rt-TDDFT) simulations, we successfully reproduced the experimental observation of the photoinduced CDW transition on the In/Si(111) surface. Our findings show that photoexcitation leads to the generation of interatomic forces, causing a structural transition through the shortening of long In-In bonds. After the transition, a switch in the In-In bonds leads to a rotation of interatomic forces, rapidly damping the oscillations in CDW modes.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Yao Liu, Fan Ye, Houbo Zhou, Xin Song, Wentao Jia, Andong Xiao, Jing Wang, Sheng Dai, Tianyu Ma, Fengxia Hu, Baogen Shen
Summary: This work reports a sensitive electric field control of first-order phase transition in the Nd0.5Sr0.5MnO3/0.71Pb(Mg1/3Nb2/3)O-3-0.29PbTiO3 heterostructure. The results reveal the phase separation character of the pristine film, and the application of electric field can manipulate the orbital ordering and the coupled electronic and magnetic phase transitions. This work provides a new approach for designing functional electronic devices.
Article
Chemistry, Multidisciplinary
Jin Zhang, Nicolas Tancogne-Dejean, Lede Xian, Emil Vinas Bostrom, Martin Claassen, Dante M. Kennes, Angel Rubio
Summary: Laser-induced ultrafast demagnetization is an interesting phenomenon with significant implications in ultrafast optoelectronics and spintronics. The spin response is found to depend on the laser wavelength and polarization due to electron correlations, band renormalizations, and charge redistributions.
Article
Chemistry, Physical
Yu Cai, Hongfu Zhu, Jiang Li, Qiwu Shi, Ye Cheng, Lei Chang, Wanxia Huang
Summary: In this study, we investigated the ultrafast terahertz response of Ti2O3 film excited by a femtosecond laser. We observed a transient photoinduced carrier generation process, followed by a fast relaxation and a slow transition process, which can be explained by nonradiative relaxation and photothermal conversion.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Physics, Multidisciplinary
Yueying Li, Xiangbin Cai, Wenjie Sun, Jiangfeng Yang, Wei Guo, Zhengbin Gu, Ye Zhu, Yuefeng Nie
Summary: Nickel-based superconductivity offers a new platform for studying high-Tc superconductivity. The crystalline quality of the perovskite phase is crucial in synthesizing high-quality superconducting nickelates. By using reactive molecular beam epitaxy, we demonstrate that atomic-scale engineering of the interface structure can effectively reduce crystalline defects in Nd-based nickelate/SrTiO3 heterostructures.
CHINESE PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Abhisek Samanta, Ahana Chakraborty, Rajdeep Sensarma
Summary: This study investigates the transition from a many-body localized phase to an ergodic phase in a spin chain with correlated random magnetic fields. Multiple statistical measures are used to determine the phase diagram, and it is found that the transition occurs at higher correlation values with increasing disorder. The average of the sample variance of magnetic fields is identified as a parameter that encodes the effects of correlated disorder.
Article
Chemistry, Multidisciplinary
Yuhan Liang, Liang Wu, Minyi Dai, Yujun Zhang, Qinghua Zhang, Jie Wang, Nian Zhang, Wei Xu, Le Zhao, Hetian Chen, Ji Ma, Jialu Wu, Yanwei Cao, Di Yi, Jing Ma, Wanjun Jiang, Jia-Mian Hu, Ce-Wen Nan, Yuan-Hua Lin
Summary: In this paper, an unconventional high-temperature anomalous Hall effect is observed in heavy metal/antiferromagnetic insulator heterostructures. This effect only occurs around the Neel temperature of the antiferromagnetic insulator and exhibits a large anomalous Hall resistivity up to 40 n omega cm. It is attributed to the emergence of a noncollinear antiferromagnetic spin texture with a nonzero net topological charge, which can be stabilized by the interplay among the collinear antiferromagnetic exchange coupling, interfacial Dyzaloshinski-Moriya interaction, thermal fluctuation, and bias magnetic field.
Article
Chemistry, Multidisciplinary
Quanzhen Zhang, Yanhui Hou, Teng Zhang, Ziqiang Xu, Zeping Huang, Peiwen Yuan, Liangguang Jia, Huixia Yang, Yuan Huang, Wei Ji, Jingsi Qiao, Xu Wu, Yeliang Wang
Summary: The researchers used scanning tunneling microscopy and spectroscopy to study the evolution of electronic structures at the interface of a phase-engineered monolayer NbSe2 heterostructure. They observed the penetration of the metallic state H-NbSe2 into the Mott insulating state T-NbSe2, with a prominent CDW proximity effect, and detected an insulating Mott gap collapse at the electronic phase transition region. Theoretical calculations suggested that this collapse could be attributed to electron doping induced by the interface, providing insights into controlling Mott insulating states through phase engineering.
Article
Materials Science, Multidisciplinary
Soren Buchenau, Florian Biebl, Benjamin Grimm-Lebsanft, Philipp Lenzen, Teguh C. Asmara, Andrivo Rusydi, Frank Lichtenberg, Michael Ruebhausen
Summary: The quasi-one-dimensional metal Sr0.95NbO3.37 undergoes a metal-to-insulator transition under laser-induced pumping of the d-d exciton. The oxygen-chain-related phonon modes are highly sensitive to this transition due to their sensitivity to structural and electronic changes. We used angle-dependent UV-resonance Raman spectroscopy to investigate the nonequilibrium oxygen-chain-related phonon dynamics and the changes in the angle-dependent midinfrared reflectance.
Article
Physics, Applied
Fengbo Yan, Fei Shao, Yu Bao, Xiaoguang Xu, Yong Jiang, Nuofu Chen, Jikun Chen
Summary: This study investigates the AC properties of different SmNiO3-based heterostructures prepared by pulsed laser deposition. By calculating the activation energy and fitting the complex impedance equivalent circuit, the dominant mechanisms of carrier transportation related to crystal structure, interface defects, and grain boundaries were identified. The strong Coulomb interaction enables the manipulation of the transport properties of SmNiO3 by increasing the input AC frequency, which has potential applications in temperature sensing and control.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Physical
Hsaio-Wen Chen, Chien- Li, Chun-Hao Ma, Ying-Hao Chu, Hsiang-Lin Liu
Summary: This paper investigates the influence of uniaxial mechanical strain on the optical properties of VO2/muscovite heterostructures. Results show linear shifts in peak positions of Raman-active phonon modes under applied strain, as well as significant changes in the metal-insulator transition temperature. The modulation of optical properties through strain engineering presents new opportunities for flexible and tunable photonic devices.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Jugal Mehta, Scott Smith, Jianheng Li, Kenneth Ainslie, Nadia Albayati, Toyanath Joshi, Pooja Rao, Yu-Hsing Cheng, Spencer Jeppson, Rahul Jangid, Evguenia Karapetrova, Donald A. Walko, Haidan Wen, David Lederman, Roopali Kukreja
Summary: The photoinduced structural dynamics of rare-earth nickelate thin films, NdNiO3 and SmNiO3, grown on (001) oriented SrTiO3 were studied using time-resolved x-ray diffraction. The recovery pathways were found to be dependent on laser fluence for NdNiO3 and distinct for the two rare-earth nickelates. The recovery of the (002) peak shifts in NdNiO3 was closely related to Ni magnetism recovery, indicating potential magnetostructural coupling.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Multidisciplinary Sciences
Aditya Sood, Xiaozhe Shen, Yin Shi, Suhas Kumar, Su Ji Park, Marc Zajac, Yifei Sun, Long-Qing Chen, Shriram Ramanathan, Xijie Wang, William C. Chueh, Aaron M. Lindenberg
Summary: Understanding the pathways and time scales underlying electrically driven insulator-metal transitions is vital for uncovering the fundamental limits of device operation. By using stroboscopic electron diffraction, researchers discovered an electrically triggered, isostructural state that forms transiently on microsecond time scales and established electrical excitation as a route for uncovering nonequilibrium and metastable phases in correlated materials. This metastable phase is similar to that formed under photoexcitation within picoseconds, suggesting a universal transformation pathway.
Article
Physics, Multidisciplinary
M. Mogi, Y. Okamura, M. Kawamura, R. Yoshimi, K. Yasuda, A. Tsukazaki, K. S. Takahashi, T. Morimoto, N. Nagaosa, M. Kawasaki, Y. Takahashi, Y. Tokura
Summary: In this study, the half-integer quantization of Hall conductance was observed in a synthetic heterostructure called a semi-magnetic topological insulator. The results provide evidence of the condensed matter realization of the parity anomaly and offer a new way to study the physics enabled by a single Dirac fermion.
Article
Physics, Multidisciplinary
Yuma Okazaki, Takehiko Oe, Minoru Kawamura, Ryutaro Yoshimi, Shuji Nakamura, Shintaro Takada, Masataka Mogi, Kei S. Takahashi, Atsushi Tsukazaki, Masashi Kawasaki, Yoshinori Tokura, Nobu-Hisa Kaneko
Summary: The quantum anomalous Hall effect (QAHE) is a transport phenomenon where the Hall resistance is quantized to the von Klitzing constant, with a precision of 10 parts per billion demonstrated in this study. By directly comparing QAHE with the quantum Hall effect (QHE), it has been confirmed that QAHE meets the required level of quantization accuracy as a primary standard of electric resistance. This high accuracy of quantization is achieved by using a weak magnetic field supplied by a permanent disc magnet to align the magnetization domains, paving the way for developing a quantum resistance standard without strong magnetic fields.
Article
Physics, Applied
Junichi Shiogai, Kohei Fujiwara, Tsutomu Nojima, Atsushi Tsukazaki
Summary: This study investigates the structural dependence of UMR in Fe-Sn heterostructure devices, revealing a weak dependence of UMR on interface configuration but an enhancement in UMR amplitude with increasing Fe-Sn layer thickness.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
Kohei Fujiwara, Koya Shibata, Shunsuke Nishimura, Junichi Shiogai, Atsushi Tsukazaki
Summary: The effect of annealing on the crystalline ordering and physical properties in thin films of Co2FeSn is reported. The annealing process induced structural changes and significantly influenced the electrical and thermoelectric transport properties. These findings highlight the importance of annealing in studying the topological band features in Co2FeSn thin films.
Article
Materials Science, Multidisciplinary
Yoshihiro D. Kato, Yoshihiro Okamura, Susumu Minami, Reika Fujimura, Masataka Mogi, Ryutaro Yoshimi, Atsushi Tsukazaki, Kei S. Takahashi, Masashi Kawasaki, Ryotaro Arita, Yoshinori Tokura, Youtarou Takahashi
Summary: This research reveals that the large intrinsic anomalous Hall effect in the ferromagnetic nodal line semimetal Fe3GeTe2 is generated by the cooperation of flat bands and band crossings near the Fermi level. The study finds that two resonance structures in the terahertz and infrared magneto-optical spectroscopy are closely related to the anomalous Hall effect.
NPJ QUANTUM MATERIALS
(2022)
Article
Multidisciplinary Sciences
Hideki Matsuoka, Tetsuro Habe, Yoshihiro Iwasa, Mikito Koshino, Masaki Nakano
Summary: In this study, a proximity-induced ferromagnetic/ferrovalley ground state with spontaneous spin-valley polarization was demonstrated in a V5Se8/NbSe2 heterostructure using Hall effect measurements. This reveals the emergence of a new quantum electronic ground state at a van der Waals (vdW) interface.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Makoto Masuko, Minoru Kawamura, Ryutaro Yoshimi, Motoaki Hirayama, Yuya Ikeda, Ryota Watanabe, James Jun He, Denis Maryenko, Atsushi Tsukazaki, Kei S. Takahashi, Masashi Kawasaki, Naoto Nagaosa, Yoshinori Tokura
Summary: In a hybrid system of topological insulator/superconductor, researchers have discovered topological superconductivity in a Bi2Te3/PdTe2 heterostructure. This heterostructure is characterized by tellurium compounds, epitaxial growth, and a small charge transfer interface.
NPJ QUANTUM MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Y. Okamura, H. Handa, R. Yoshimi, A. Tsukazaki, K. S. Takahashi, M. Kawasaki, Y. Tokura, Y. Takahashi
Summary: This study investigates the lattice and charge dynamics in ferroelectric semiconductor thin films using terahertz time-domain spectroscopy. The results show that there is a temperature anomaly in the resonant frequency of the phonons, indicating a displacive-type ferroelectric transition. The study also reveals an enhancement of ferroelectricity in the films and the ability of low-energy phonons to induce a large dielectric constant even in metallic states.
NPJ QUANTUM MATERIALS
(2022)
Article
Physics, Applied
Junichi Shiogai, Atsushi Tsukazaki
Summary: In this study, a freestanding single-crystalline FeSe membrane was prepared using a water-soluble Sr3Al2O6 sacrificial layer as a growth template. The FeSe membrane was fully relaxed with minimal degradation of its structural properties during the lift-off process. The freestanding FeSe membrane exhibited superconductivity below 4.2 K, while it was not observed in a compressed thin-film form.
APPLIED PHYSICS LETTERS
(2023)
Letter
Physics, Multidisciplinary
Minoru Kawamura, Masataka Mogi, Ryutaro Yoshimi, Takahiro Morimoto, Kei S. Takahashi, Atsushi Tsukazaki, Naoto Nagaosa, Masashi Kawasaki, Yoshinori Tokura
Summary: Adiabatic charge pumping is observed in a thin-film magnetic heterostructure of topological insulators, confirming the theoretical prediction of topological magnetoelectric effect. The pumped charge is proportional to the surface Hall conductivity, providing clues for its direct observation.
Article
Materials Science, Multidisciplinary
Junichi Shiogai, Junya Ikeda, Kohei Fujiwara, Takeshi Seki, Koki Takanashi, Atsushi Tsukazaki
Summary: By measuring Hall resistance, we found that the Co3Sn2S2 thin films have a large coercivity, which is attributed to the uniform crystallinity within grains and strong domain-wall pinning at grain boundaries. This is important for controlling the nucleation, manipulation, and detection of single domain walls in thin-film devices.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Physics, Applied
Kohei Fujiwara, Junya Ikeda, Shun Ito, Atsushi Tsukazaki
Summary: Solid-liquid interfaces composed of functional inorganic materials and liquid electrolytes exhibit interesting responses when an electric bias is applied. By using an electric-double-layer device on a thin-film channel of magnetic Weyl semimetal Co3Sn2S2 with an ionic liquid gate electrolyte, it is shown that the thickness of the conducting channel can be effectively reduced with a negative gate voltage. This finding allows for the examination of the thickness dependence of the anomalous transport properties of Co3Sn2S2 in a single sample.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Masamichi Negishi, Kohei Fujiwara, Atsushi Tsukazaki
Summary: Pulsed-laser deposition is a widely used method to fabricate complex oxide thin films, and film composition is regulated by various conditions. This study reports an experimental scheme to tune the composition ratio in Mg-Ir-O films fabricated by pulsed-laser deposition. By examining different parameters, a wide range of composition ratio was regulated in the films, and a spinel-related crystalline phase was discovered in the Mg-rich compositions.
Article
Multidisciplinary Sciences
Kohei Fujiwara, Yasuyuki Kato, Hitoshi Abe, Shun Noguchi, Junichi Shiogai, Yasuhiro Niwa, Hiroshi Kumigashira, Yukitoshi Motome, Atsushi Tsukazaki
Summary: Amorphous semiconductors are widely used in electronic and energy-conversion devices. This study reveals that the short-range crystalline order in amorphous Fe-Sn films contributes to anomalous electrical and magneto-thermoelectric properties. This finding sheds light on the topology of amorphous materials and may enable the realization of functional topological amorphous electronic devices.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Motoki Osada, Kohei Fujiwara, Tsutomu Nojima, Atsushi Tsukazaki
Summary: The nickelate superconductor with infinite NiO2 layer was synthesized by reducing the perovskite precursor phase through topochemical reduction. By increasing the reduction temperature, La1-xSrxNiO2 films transformed from the insulating state to the superconducting state, with a maximum onset superconducting transition temperature T onset c of about 14K at x = 0.20. The electrical conduction in NiO2 planes is found to be a sensitive parameter for optimizing the reduction state. The systematic optimization of reduction temperature resulted in an expanded superconducting dome in the phase diagram with higher T onset c and wider x range (0.12 x 0.28) compared to previous reports.
PHYSICAL REVIEW MATERIALS
(2023)
