Article
Materials Science, Multidisciplinary
Yangmu Li, A. Sapkota, P. M. Lozano, Zengyi Du, Hui Li, Zebin Wu, Asish K. Kundu, R. J. Koch, Lijun Wu, B. L. Winn, Songxue Chi, M. Matsuda, M. Frontzek, E. S. Bozin, Yimei Zhu, I. Bozovic, Abhay N. Pasupathy, Ilya K. Drozdov, Kazuhiro Fujita, G. D. Gu, I. A. Zaliznyak, Qiang Li, J. M. Tranquada
Summary: The interpretation of how superconductivity disappears in cuprates at large hole doping has been controversial. To address this issue, we studied La2-xSrxCuO4 (LSCO) samples with x=0.25. Our experimental results show that in LSCO crystals with x=0.25, there are two superconducting transition temperatures, Tc1 and Tc2, where Tc1 is 38.5 K and indicates the onset of diamagnetism, while Tc2 is 18 K and represents full bulk shielding. Moreover, we found that in strongly overdoped cuprates, superconductivity initially develops within disconnected self-organized grains characterized by reduced hole concentration, and there are still some regions with pairing correlations, but they are too dilute to support superconducting order.
Article
Physics, Applied
L. H. Yang, B. Da, H. Yoshikawa, S. Tanuma, J. Hu, J. W. Liu, D. M. Tang, Z. J. Ding
Summary: This study investigated the electron inelastic mean free path (IMFP) and elastic mean free path (EMFP) in graphene using an improved approximation within a classical electron trajectory framework. A unique hump feature was observed in the IMFP results of multilayer graphene, attributed to the out-of-plane mode of the pi + sigma plasmon, while it was absent in monolayer graphene. The obtained EMFPs were found to be one order of magnitude higher than previously reported results.
APPLIED PHYSICS LETTERS
(2021)
Article
Nanoscience & Nanotechnology
Roberto Fallica, Nicola Mahne, Thierry Conard, Anja Vanleenhove, Danilo de Simone, Stefano Nannarone
Summary: In this study, a modified substrate-overlay technique was used to evaluate the inelastic mean free path of electrons in photoresists, which is important for lithography patterning and electron microscopy. The results showed that the mean free path of electrons in extreme ultraviolet lithography was between 1 and 2 nm, and it increased at higher kinetic energy.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Physics, Applied
Jo Okada, Hajime Tanaka, Nobuya Mori
Summary: A numerical calculation method is proposed to compute the transport mean free path of semiconductor nanosheets with surface roughness. The method extracts the mean free path from the statistical average of the logarithm of the dimensionless resistance. It is applicable to a wide range of channel length and shows a dependence on the channel thickness.
APPLIED PHYSICS EXPRESS
(2023)
Article
Chemistry, Multidisciplinary
Ankit Negi, Alejandro Rodriguez, Xuanyi Zhang, Andrew H. H. Comstock, Cong Yang, Dali Sun, Xiaoning Jiang, Divine Kumah, Ming Hu, Jun Liu
Summary: In this study, the thermal conductivity and phonon mean free path (MFP) distribution of barium titanate (BTO) were determined through experimental measurements and first-principles modeling. The results show that phonons with sub-100 nm MFP dominate the thermal transport in BTO, and phonons with MFP exceeding 10 nm contribute approximately 35% to the total thermal conductivity. These findings are consistent with the theoretical predictions of other crystals with strong anharmonicity.
Article
Chemistry, Physical
Jianchun Sun, Donglin Guo, Hongli Zhang, Zhengmeng Xu, Chunhong Li, Kejian Li, Bin Shao, Dengming Chen, Yilong Ma
Summary: By adjusting the size of the grain boundary, the improvement of ZT can be achieved. The thermoelectric performance of SnSe under different electron/phonon transport mechanisms is evaluated by considering the full electron-phonon interactions. Our work reveals the enhancement of ZT through the electron filtering effect and demonstrates a computational framework for accurately calculating thermoelectric performance.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Microscopy
Cathal Cassidy, Makoto Tokoro Schreiber, Marco Beleggia, Jun Yamasaki, Hidehito Adaniya, Tsumoru Shintake
Summary: In this work, the factors influencing mean free path values obtained from off-axis electron holography measurements are explored. The theoretical analysis shows that the mean amplitude reconstructed from off-axis holograms is only determined by the coherent portion of the direct beam, and this finding is confirmed by experimental studies. The measurements of different materials also demonstrate that the contributions of elastic and inelastic scattering to the total mean free path are in agreement with theoretical expectations. It is concluded that the mean amplitude signal and the associated mean free path values derived from off-axis holography reconstructions are not affected by experimental collection angles or enhanced sensitivity to low-loss phonon scattering.
Article
Multidisciplinary Sciences
Ivan Specht, Kian Sani, Yolanda Botti-Lodovico, Michael Hughes, Kristin Heumann, Amy Bronson, John Marshall, Emily Baron, Eric Parrie, Olivia Glennon, Ben Fry, Andres Colubri, Pardis C. Sabeti
Summary: During COVID-19, allocating testing resources to close contacts of institution members can effectively control case counts.
SCIENTIFIC REPORTS
(2022)
Article
Microscopy
Adham Basha, George Levi, Tamir Amrani, Yang Li, Guy Ankonina, Pini Shekhter, Lior Kornblum, Ilan Goldfarb, Amit Kohn
Summary: Quantitative transmission electron microscopy relies on accurate sample thickness measurement. The most common method is Electron Energy Loss Spectroscopy, but it is measured in units dependent on the material and energy. A fast and precise method using a crystalline Si substrate is proposed for oxide thin films, providing reliable results for both inelastic and elastic mean free paths.
Article
Chemistry, Physical
Donglin Guo, Hongli Zhang, Zhengmeng Xu, Chunhong Li, Kejian Li, Bin Shao, Dengming Chen, Yilong Ma, Jianchun Sun
Summary: The study shows that by reducing the phonon thermal conductivity, enhancing the electronic performance, and considering various mean free paths, the thermoelectric properties of PbTe can be effectively improved. The contribution to electrical transport mainly comes from mean free path scattering, while thermal transport is mainly influenced by phonon scattering. Significant enhancement in the ZT value for p-type is observed when the hole/photon mean free path is 10 nm.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Yanguang Zhou, Baoling Huang, Bing-Yang Cao
Summary: Recent experiments indicate that the thermal conductivity of amorphous metal-organic frameworks can be higher than their crystalline counterparts due to higher atomic number density. The study shows that amorphous ZIF-4 has longer mean free path vibrations and increased volumetric heat capacity compared to crystalline ZIF-4, leading to a potentially 1.7 times higher thermal conductivity. Both amorphous and crystalline ZIF-4 exhibit weak temperature-dependent thermal conductivity, attributed to different structural characteristics and heat carrier properties.
MATERIALS TODAY PHYSICS
(2021)
Article
Chemistry, Physical
Nicolas Pauly
Summary: Calculations were performed on the local inverse inelastic mean free path (local-IIMFP) for electrons crossing a medium-medium interface under various conditions, resulting in observed subtle variations in the interface excitation parameter.
SURFACE AND INTERFACE ANALYSIS
(2023)
Article
Mechanics
Yifeng Tian, Yen Ting Lin, Marian Anghel, Daniel Livescu
Summary: Developing reduced-order models for turbulent flows, which contain dynamics over a wide range of scales, is a challenging problem due to the limited knowledge of Mori-Zwanzig (MZ) operators. In this work, a data-driven learning algorithm based on Koopman's description of dynamical systems and Mori's linear projection operator is applied to fully resolved isotropic turbulence datasets to extract the Mori-Zwanzig operators. The results show that prediction errors in numerical experiments are affected by the choice of observables and can be reduced by including the past history of observables in the memory kernel.
Article
Mechanics
Maximilian Krause, Tarkes Dora Pallicity, Thomas Boehlke
Summary: This paper derives analytical equations for the second moments of local fields in particulate composites with isotropic phases. Using the Mori-Tanaka approach, the Hashin-Shtrikman bounds, and the singular approximation, explicit expressions are provided. The results are compared to full-field simulations, showing that the Hashin-Shtrikman covariance is not suitable for predicting behavior under deviatoric loadings, while the singular approximation and Mori-Tanaka methods yield sensible approximations for the second moment of matrix strain.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2023)
Article
Materials Science, Multidisciplinary
J. M. Gong, K. Tokesi, X. Liu, B. Da, H. Yoshikawa, S. Tanuma, Z. J. Ding
Summary: In this study, we used the relativistic dielectric response theory to obtain the inelastic mean free path (IMFP) and stopping power of hafnium dioxide (HfO2). The energy loss function derived from reflection electron energy loss spectroscopy spectrum was applied for the first time. Two algorithms were utilized to expand the optical energy loss function into the (q, omega)-plane. The results showed consistency at high electron energies, but differences at low electron energies due to the consideration of the finite plasmon lifetimes effect.
RESULTS IN PHYSICS
(2023)
Article
Physics, Multidisciplinary
Hao Jin, Alessandro Narduzzo, Minoru Nohara, Hidenori Takagi, N. E. Hussey, Kamran Behnia
Summary: In this study, the thermoelectric response in heavily overdoped, non-superconducting La1.67Sr0.33CuO4 was investigated. Despite the electron-like curvature of the Fermi surface, the positive Seebeck coefficient at low temperatures was observed, which is attributed to the non-trivial energy dependence of the scattering time. It is argued that this feature implies a strong electron-hole asymmetry, hindering the formation of Cooper pairs in the superconducting ground state at lower doping levels.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2021)
Article
Physics, Multidisciplinary
Kensuke Takaki, Mayu Yamamoto, Masamichi Nakajima, Tetsuya Takeuchi, Hoang Yen Nguyen, Minoru Nohara, Yasuhiro Kishioji, Takahiro Fujii, Kentaro Yoshino, Shigeki Miyasaka, Kazutaka Kudo
Summary: Novel CdI2-type compounds Pt(Bi(1-x)Ch(x))(2) (Ch = Se, Te) were synthesized, and it was found that the partial substitution of Ch for Bi induces a structural phase transition. The layered structure of Pt(Bi(1-x)Ch(x))(2) is formed by edge-sharing PtBi6 octahedra. Magnetization, electrical resistivity, and specific heat measurements confirmed the emergence of superconductivity at higher temperatures in Pt(Bi1-xSex)(2) and Pt(Bi1-xTex)(2), which are located near the polar-nonpolar structural phase boundary.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2022)
Article
Physics, Condensed Matter
Yves Noat, Alain Mauger, Minoru Nohara, Hiroshi Eisaki, Shigeyuki Ishida, William Sacks
Summary: This study revisits the experimental data of four different compounds and finds that the magnetic susceptibility can be described by the same function for all materials. It is observed that the magnetic and electronic contributions reveal the existence of the pseudogap. The analysis suggests a qualitative change of behavior between underdoped and overdoped regimes.
SOLID STATE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
M. Berben, S. Smit, C. Duffy, Y-T Hsu, L. Bawden, F. Heringa, F. Gerritsen, S. Cassanelli, X. Feng, S. Bron, E. van Heumen, Y. Huang, F. Bertran, T. K. Kim, C. Cacho, A. Carrington, M. S. Golden, N. E. Hussey
Summary: Once doped away from their parent Mott insulating state, the hole-doped cuprates enter into many varied and exotic phases. The onset temperature of each phase is then plotted versus p-the number of doped holes per copper atom-to form a representative phase diagram. Apart from differences in the absolute temperature scales among the various families, the resultant phase diagrams are strikingly similar. In particular, the p values corresponding to optimal doping and to the end of the pseudogap phase are essentially the same for all cuprate families except for the single-layer Bi-based cuprate Bi2+z-yPbySr2-x-zLaxCuO6+delta (Bi2201). This anomaly arises partly due to the complex stoichiometry of this material and also to the different p values inferred from disparate measurements performed on samples with comparable superconducting transition temperatures T-c. Here, by combining measurements of in-plane resistivity in zero and high magnetic fields with angle-resolved photoemission spectroscopy studies, we argue that the phase diagram of Bi2201 may actually be similar to that realized in other families, supporting the notion of universality of p(opt) and p* in all hole-doped cuprates.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Physics, Multidisciplinary
Y. -t. Hsu, M. Osada, B. Y. Wang, M. Berben, C. Duffy, S. P. Harvey, K. Lee, D. Li, S. Wiedmann, H. Y. Hwang, N. E. Hussey
Summary: This study investigates the resistivity behavior in undoped nickelate materials and examines the impact of disorder and doping on its temperature dependence. The results reveal that the level of doping has little correlation with the magnitude and onset temperature of the resistivity upturn, while the different rare-earth families play a crucial role in the evolution of the insulating behavior.
FRONTIERS IN PHYSICS
(2022)
Article
Physics, Multidisciplinary
Jake Ayres, Matija Culo, Jonathan Buhot, Bence Bernath, Shigeru Kasahara, Yuji Matsuda, Takasada Shibauchi, Antony Carrington, Sven Friedemann, Nigel E. Hussey
Summary: In this study, the authors investigate the resistive properties of sulfur-doped FeSe under applied pressure and find evidence of a decoupling of electronic nematicity and magnetic fluctuations in this system.
COMMUNICATIONS PHYSICS
(2022)
Review
Multidisciplinary Sciences
Philip W. Phillips, Nigel E. Hussey, Peter Abbamonte
Summary: Strange metals are a class of materials that defy the traditional temperature dependence of electrical resistivity at both low and high temperatures. By studying the transport and spectroscopic data of these materials, we aim to identify a unifying physical principle, with special focus on quantum criticality, Planckian dissipation, Mottness, and the possible requirement of a new gauge principle to explain the nonlocal transport observed in these materials.
Article
Physics, Multidisciplinary
Takumi Mitsuoka, Yu Takahashi, Takeshi Suzuki, Mario Okawa, Hidenori Takagi, Naoyuki Katayama, Hiroshi Sawa, Minoru Nohara, Mari Watanabe, Jiadi Xu, Qianhui Ren, Masami Fujisawa, Teruto Kanai, Jiro Itatani, Kozo Okazaki, Shik Shin, Takashi Mizokawa
Summary: The photoinduced semimetal phase of Ta2Ni1-xCoxSe5 (x = 0.0 and 0.1) was studied using time-resolved angle-resolved photoemission spectroscopy. The observed band dispersions roughly agree with the generalized gradient approximation (GGA) calculation, but fail to reproduce the band gap at ambient conditions. This suggests that the electron-hole interaction, not properly included in GGA, is screened out by the photoexcited carriers. No indication of pseudogap was found. The conduction and valence bands exhibit quasi one-dimensional Fermi surfaces with similar momentum positions, indicating a quasi one-dimensional line-node semimetal.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2023)
Article
Physics, Multidisciplinary
Yu Takahashi, Takeshi Suzuki, Masaki Hattori, Mario Okawa, Hidenori Takagi, Naoyuki Katayama, Hiroshi Sawa, Minoru Nohara, Yigui Zhong, Kecheng Liu, Teruto Kanai, Jiro Itatani, Shik Shin, Kozo Okazaki, Takashi Mizokawa
Summary: In this study, the temporal evolution and fluence dependence of band structure in Ta2Ni0.9Co0.1Se5 were investigated using tr-ARPES. The results show the formation of a photoinduced semimetal phase and a partial gap/pseudogap, indicating the vital role of lattice fluctuations in the residual pseudogap after photoexcitation.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2023)
Article
Materials Science, Multidisciplinary
Raito Nakamura, Azumi Ishita, Jin Nakamura, Hiroto Ohta, Yuya Haraguchi, Hiroko Aruga Katori, Hajime Ishikawa, Akira Matsuo, Koichi Kindo, Minoru Nohara, Akihiko Ikeda
Summary: The 122 compounds of the Eu(Co1-xNix)2P2 solid solution exhibit a valence transition between divalent and intermediate valence states at Eu, which is related to structural transition, magnetism and formation of P-P dimers. The effect of high magnetic fields on the Eu valence-fluctuating regime samples is investigated, revealing that magnetostriction and magnetization increase smoothly with the magnetic fields. The results indicate that the Eu valence changes manifest themselves in magnetization curves at high magnetic fields.
Article
Materials Science, Multidisciplinary
H. Okamura, T. Mizokawa, K. Miki, Y. Matsui, N. Noguchi, N. Katayama, H. Sawa, M. Nohara, Y. Lu, H. Takagi, Y. Ikemoto, T. Moriwaki
Summary: The effect of pressure on the electronic state of Ta2NiSe5 has been studied. It was found that the energy gap becomes narrower and the excitonic peak diminishes with increasing pressure. After a structural transition, Ta2NiSe5 becomes a semimetal. This phenomenon is mainly attributed to the weakening of excitonic correlation with pressure.
Article
Physics, Multidisciplinary
R. D. H. Hinlopen, F. A. Hinlopen, J. Ayres, N. E. Hussey
Summary: Strange metals exhibit a linear increase in resistivity with magnetic field. The presence of strong anisotropic scattering can generate magnetoresistance, but it saturates at high magnetic field strengths. A bounded sector on the Fermi surface is required for the realization of quadratic-to-linear magnetoresistance.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
Isao Ishii, Yuki Kurata, Yuki Wada, Minoru Nohara, Takashi Suzuki, Koji Araki, Alexander V. Andreev
Summary: We conducted ultrasonic measurements on ErNiAl and discovered a phase transition at T-Q, below the antiferromagnetic transition temperature T-N. This transition is characterized by a significant elastic softening of C-66 and ultrasonic attenuation, indicating the presence of O-xy-type ferroquadrupolar ordering in a magnetically ordered state at zero magnetic field.
Article
Physics, Multidisciplinary
J. F. Linnartz, C. S. A. Mueller, Yu-Te Hsu, C. Breth Nielsen, M. Bremholm, N. E. Hussey, A. Carrington, S. Wiedmann
Summary: This study provides a detailed investigation of the magnetic behavior of WTe2, accurately determining its Fermi surface and explaining its unusual electronic properties. The Russian-doll nested Fermi surface model is confirmed, and it is found that impurity damping solely determines the onset of magnetic breakdown in WTe2.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
Takeshi Suzuki, Yasushi Shinohara, Yangfan Lu, Mari Watanabe, Jiadi Xu, Kenichi L. Ishikawa, Hide Takagi, Minoru Nohara, Naoyuki Katayama, Hiroshi Sawa, Masami Fujisawa, Teruto Kanai, Jiro Itatani, Takashi Mizokawa, Shik Shin, Kozo Okazaki
Summary: Researchers used the FDARPES technique to discover that in the photoinduced insulator-to-metal transition of Ta2NiSe5, the lattice modulation induced by the 2 THz phonon mode is the most relevant for the emergence of the photoinduced semimetallic state. Additionally, in the transient state, both semimetallic and semiconducting bands coexist, and FDARPES spectra can selectively detect the phonon-specific couplings to these coexistent band structures by resolving them in the frequency domain.
