Article
Materials Science, Multidisciplinary
Daniel J. Schultz, Adarsh S. Patri, Yong Baek Kim
Summary: The study focuses on the quasi-quartet multipolar impurity in the multipolar Kondo problem, revealing that in tetragonal crystal field environments, the local moment can support different orders of multipolar moments and interact with conduction electrons in entangled spin and orbital states. Using renormalization group analysis, the research uncovers emergent quantum ground states characterized by nontrivial fixed points.
Article
Optics
Keisuke Totsuka
Summary: We study the ground-state properties of the SU(N) generalization of the Kondo lattice model in one dimension under strong coupling. The two cases, both ferromagnetic and antiferromagnetic Kondo coupling JK, can be realized using alkaline-earth-metal-like cold gases in optical lattices. By carrying out strong-coupling expansion, we identify two insulating phases, one of which is the SU(N) analog of the well-known gapped Kondo singlet phase. We rigorously establish that the ground state is ferromagnetic in the low-density region (for JK < 0) or the high-density region (for JK > 0). These results are explained by generalizing the double-exchange mechanism to SU(N) spins. Possible realizations of Bose-Fermi supersymmetry SU(N|1) in the (generalized) SU(N) Kondo lattice model are also discussed.
Article
Physics, Multidisciplinary
Jordi Pera, Joaquim Casulleras, Jordi Boronat
Summary: We present exact analytic results for the energy of a SU(N) repulsive Fermi gas as a function of the spin-channel occupation at second order in the gas parameter. This is an extension of previous results that now incorporates the degree of polarization of the system. The magnetic properties of the gas can be obtained, free from numerical uncertainties. Estimations for Fermi gases of Yb and Sr with spin 5/2 and 9/2, respectively, are reported.
Article
Physics, Multidisciplinary
Guangjie Li, Yuval Oreg, Jukka I. Vaeyrynen
Summary: A Coulomb blockaded M-Majorana island coupled to normal metal leads realizes a novel type of Kondo effect where the effective impurity spin transforms under the orthogonal group SO(M). The impurity spin stems from the nonlocal topological ground state degeneracy of the island and thus the effect is known as the topological Kondo effect. We introduce a physically motivated N-channel generalization of the topological Kondo model.
PHYSICAL REVIEW LETTERS
(2023)
Article
Optics
Aaron Merlin Mueller, Miklos Lajko, Florian Schreck, Frederic Mila, Jiri Minar
Summary: The study investigates species-selective cooling of a trapped SU(N) Fermi gas through entropy redistribution during adiabatic loading of an optical lattice, demonstrating improved cooling effects. Optimal performance is achieved when all atomic levels experience the same potential, outside of a specific dimple region. Specific quantitative discussions on achieving state-selective trapping in Sr-87 and Yb-173 using existing experimental techniques are provided.
Article
Materials Science, Multidisciplinary
Hironobu Yoshida, Hosho Katsura
Summary: In this study, we investigate the generalization of eta-pairing states to N-particle systems in a chain of N-component fermions and demonstrate that these states are exact eigenstates of an extended SU(N) Hubbard model. We observe that the correlation behavior of these states differs qualitatively for even and odd N.
Article
Multidisciplinary Sciences
Daniele Guerci, Jie Wang, Jiawei Zang, Jennifer Cano, Andrew Millis
Summary: We theoretically investigate the interaction between magnetism and a heavy Fermi liquid in the AB-stacked transition metal dichalcogenide bilayer system MoTe2/WSe2. The interlayer electron transfer leads to a chiral Kondo exchange, resulting in a strong dependence of the Kondo temperature on carrier concentration and anomalous Hall effect due to topological hybridization gap. Our findings provide concrete experimental predictions for ongoing experiments on MoTe2/WSe2 bilayer heterostructures and offer a controlled route to observe a topological selective Mott transition.
Article
Physics, Multidisciplinary
D. Takegami, C-Y Kuo, K. Kasebayashi, J-G Kim, C. F. Chang, C. E. Liu, C. N. Wu, D. Kasinathan, S. G. Altendorf, K. Hoefer, F. Meneghin, A. Marino, Y. F. Liao, K. D. Tsuei, C. T. Chen, K-T Ko, A. Guenther, S. G. Ebbinghaus, J. W. Seo, D. H. Lee, G. Ryu, A. C. Komarek, S. Sugano, Y. Shimakawa, A. Tanaka, T. Mizokawa, J. Kunes, L. H. Tjeng, A. Hariki
Summary: We present a comprehensive study of CaCu3Ru4O12 using bulk sensitive hard and soft x-ray spectroscopy combined with local-density approximation + dynamical mean-field theory (DMFT) calculations. Correlation effects on both the Cu and Ru ions can be observed. Based on the analysis of Cu 2p corelevel spectra, we infer the presence of magnetic Cu2+ ions hybridized with itinerant electrons. The photon energy dependence of the valence band allows us to optimize the DMFT calculations, indicating that CaCu3Ru4O12 can be classified as a Kondo system with a Kondo temperature in the range of 500-1000 K.
Article
Optics
B. Abeln, K. Sponselee, M. Diem, N. Pintul, K. Sengstock, C. Becker
Summary: In this study, interisotope interorbital interactions between atoms in Yb-171 and Yb-173 mixture were characterized. The elastic interaction between Yb-173(e)-Yb-171(g) and Yb-173(g)-Yb-171(e) was found to be weakly attractive, with different two-body decay coefficients. By comparing different spin mixtures, the SU(2)⨂SU(6) symmetry of the elastic interactions was experimentally demonstrated. Additionally, the interorbital spin-exchange interaction in Yb-171 was measured and confirmed to be antiferromagnetic.
Article
Physics, Multidisciplinary
Andreas Osterloh, Juan Polo, Wayne J. Chetcuti, Luigi Amico
Summary: In this study, we investigate a gas of repulsive N-component fermions confined in a ring-shaped potential, subjected to an effective magnetic field. Using the Bethe ansatz scheme, we calculate the two-point correlation matrix and the one-particle density matrix for large repulsion strengths. Our results are applicable to mesoscopic systems with a finite but sufficiently large number of particles and system size, which are not accessible by numerical methods. We analyze the momentum distribution of the system and its specific dependence on the interaction, magnetic field, and number of components N. In the field of cold atoms, we perform exact computations of the correlation matrix to determine the interference patterns produced when releasing cold atoms from ring traps.
Article
Materials Science, Multidisciplinary
Guangjie Li, Elio J. Koenig, Jukka I. Vayrynen
Summary: This study proposes a mesoscopic setup for the Kondo effect that can produce emergent anyons, including Majorana fermions, Fibonacci anyons, and Z3 parafermions, even without perfect channel symmetry. The model is mapped to the multichannel Kondo effect associated with an internal SU(2) symmetry, and the scaling of various observables, including conductance, is predicted using conformal field theory. This work not only provides a platform for robust Kondo-based anyons, but also sheds light on the physics of strongly correlated materials with competing order parameters.
Article
Physics, Condensed Matter
Bei Xu, Shoufa Sun, Qiang Gu
Summary: In this study, we investigate the Kondo effect of a spin-3/2 Fermi gas and provide a detailed calculation of the impurity resistance and ground state energy based on the s-d exchange model. We find that the impurity resistance increases logarithmically with decreasing temperature and the ground state energy is influenced by the type of coupling. Our results also suggest that larger spins are more easily screened in the Kondo phase.
PHYSICA B-CONDENSED MATTER
(2022)
Article
Materials Science, Multidisciplinary
Kazuhiko Tsutsumi, Yoshimichi Teratani, Kaiji Motoyama, Rui Sakano, Akira Oguri
Summary: This study investigates the effects of bias and tunneling asymmetries on the nonlinear current in a quantum dot within the Fermi liquid regime. Through an exact low-energy expansion, it is found that three-body correlation functions play a crucial role in the V3 terms of the current, and their coupling to the nonlinear current depends on the bias and tunneling asymmetries. The number of independent components of the three-body correlation functions increases with the internal degrees of freedom in the quantum dot, resulting in a variety of low-energy transport behaviors.
Article
Astronomy & Astrophysics
Erik Khastyan, Sergey Krivonos, Armen Nersessian
Summary: This article introduces the formulation of su(1, N vertical bar M) superconformal mechanics using phase superspace and proposes a scheme to construct superintegrable systems. The article also discusses the differences between oscillatorlike and Coulomb-like systems with different dynamical superalgebras.
Article
Astronomy & Astrophysics
Renato M. Fonseca
Summary: This work provides the necessary and sufficient conditions for two SU(n) invariant potentials to be bounded from below, and discusses models with different scalar representations, particularly the ones with the gauge group SU(2) and the scalar representations 1, 2, and 3.
Article
Physics, Multidisciplinary
Jose Lebreuilly, Camille Aron, Christophe Mora
PHYSICAL REVIEW LETTERS
(2019)
Article
Physics, Applied
Udson C. Mendes, Sebastien Jezouin, Philippe Joyez, Bertrand Reulet, Alexandre Blais, Fabien Portier, Christophe Mora, Carles Altimiras
PHYSICAL REVIEW APPLIED
(2019)
Review
Physics, Multidisciplinary
Michele Filippone, Arthur Marguerite, Karyn Le Hur, Gwendal Feve, Christophe Mora
Article
Physics, Multidisciplinary
Daniele Guerci, Pascal Simon, Christophe Mora
PHYSICAL REVIEW LETTERS
(2020)
Article
Physics, Multidisciplinary
Jacob F. Steiner, Christophe Mora, Katharina J. Franke, Felix von Oppen
Summary: This study demonstrates that dilute Yu-Shiba-Rusinov (YSR) chains are not only promising for realizing Majorana end states, but also a versatile platform for quantum magnetism and correlated electron dynamics.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Edouard Boulat, Winston Pouse, David Goldhaber-Gordon, Andrew K. Mitchell, Christophe Mora, D. B. Karki
Summary: In this paper, the authors investigate the emergence of Z3 parafermions and scattering of fractional charges in a charge-Kondo model at a critical point using bosonization and Bethe-ansatz solution. They also present numerical renormalization group calculations and show that the predicted behavior of conductance agrees with experimental results.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Krystof Kolar, Gal Shavit, Christophe Mora, Yuval Oreg, Felix von Oppen
Summary: The emergence of correlated insulating phases in magic-angle twisted bilayer graphene is highly dependent on the sample. We derive an Anderson theorem that describes the robustness of the Kramers intervalley coherent (K-IVC) state against PT (particle-hole conjugation) and time reversal perturbations, which is a prime candidate for describing correlated insulators at even fillings of the moire flat bands. We find that the K-IVC gap is robust against PT-odd perturbations, but PT-even perturbations can induce subgap states and reduce or eliminate the gap. This result allows us to classify the stability of the K-IVC state against experimentally relevant perturbations.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Yuncheng Mao, Daniele Guerci, Christophe Mora
Summary: Stacking three monolayers of graphene with a twist creates two moire patterns, resulting in a moire-of-moire structure at larger distances. A low-energy theory is developed to describe the spectrum beyond the moire length scale, which includes one Dirac cone at the FM point and two weakly gapped points at KM and K'M in each valley of the underlying graphene. The model exhibits spatially varying velocities and small gaps in the moire-of-moire unit cell, and the resulting spectrum is protected by time-reversal and twofold-rotation symmetries.
Article
Materials Science, Multidisciplinary
Gal Shavit, Krystof Kolar, Christophe Mora, Felix von Oppen, Yuval Oreg
Summary: The effects of random strain variations on correlated insulators in magic-angle twisted bilayer graphene are explored. It is found that strain disorder can strongly suppress or even eliminate the spectral gap while maintaining intervalley coherence.
Article
Materials Science, Multidisciplinary
Deepak B. Karki, Edouard Boulat, Christophe Mora
Summary: Quantum Hall edge channels can form correlated impurity models when combined with metallic regions, and a mapping to the boundary sine-Gordon model can be established under high transparency of the quantum point contacts. The device is predicted to produce fractional charges under finite voltage bias.
Article
Materials Science, Multidisciplinary
Tom Morel, June-Young M. Lee, H-S Sim, Christophe Mora
Summary: One remarkable feature of strongly correlated systems is the phenomenon of fractionalization, where quasiparticles carry only a fraction of the charge or spin of the elementary constituents. This phenomenon is important in the fractional quantum Hall effect. This paper discusses the observation of fractionalization and anyonic statistics in the integer quantum Hall effect coupled to a metallic island. A continuous fractional emitter is proposed, and its full counting statistics of noninteger charges is obtained. The mixing of two fractional beams is characterized through a quantum point contact beam splitter.
Article
Physics, Multidisciplinary
Daniele Guerci, Pascal Simon, Christophe Mora
Summary: Twisted trilayer graphene (TTG) has recently been discovered as a fascinating platform to study correlated and exotic superconducting phases. It hosts a zero-energy higher-order Van Hove singularity that is stronger than predicted in twisted bilayer graphene, and this singularity can be tuned with only the twist angle and a perpendicular electric field. The emergence of this singularity is a result of the merging of Van Hove singularities and Dirac cones at zero energy, going beyond the recent classifications of Van Hove singularities in single-band models. This unique structure provides an unprecedented platform for studying correlation and superconductivity.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
Tom Morel, Christophe Mora
Summary: The study reveals that introducing different periodicities into a Josephson junction in a resistor environment can lead to competition between different phases, resulting in nonmonotonic temperature dependence of the differential resistance. This phenomenon is particularly significant at low temperatures and can be confirmed by fermionization and models such as helical wires.
Article
Materials Science, Multidisciplinary
Daniele Guerci, Pascal Simon, Christophe Mora
Summary: By analyzing the band structure of twisted bilayer graphene, we observe changes in orbital magnetic susceptibility under different doping conditions, including the transition from diamagnetism to paramagnetism and the logarithmic divergence at the van Hove singularity. The enhanced paramagnetism at the van Hove singularity is influenced by the angle of twist, while the in-plane susceptibility shows a logarithmic divergence at the magic angle and is enhanced near the magic-angle region under finite doping conditions.
Article
Physics, Multidisciplinary
H. Duprez, F. Pierre, E. Sivre, A. Aassime, F. D. Parmentier, A. Cavanna, A. Ouerghi, U. Gennser, I Safi, C. Mora, A. Anthore
Summary: The study investigates the dynamical Coulomb blockade suppression of electrical conductance across an electronic quantum channel subject to a temperature difference. By analyzing experimental data and theoretical models, researchers were able to explain the variations in conductance under different temperature conditions effectively.
PHYSICAL REVIEW RESEARCH
(2021)
