Article
Multidisciplinary Sciences
Annika Kurzmann, Yaakov Kleeorin, Chuyao Tong, Rebekka Garreis, Angelika Knothe, Marius Eich, Christopher Mittag, Carolin Gold, Folkert Kornelis de Vries, Kenji Watanabe, Takashi Taniguchi, Vladimir Fal'ko, Yigal Meir, Thomas Ihn, Klaus Ensslin
Summary: The study explores the interplay between spin-orbit interaction and the Kondo effect, revealing the possibility of underscreened Kondo effects in bilayer graphene quantum dots. Unlike carbon nanotubes, a different experimental platform is employed to investigate Kondo physics in a planar carbon material.
NATURE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Jia-Ning Wang, Wang-Huai Zhou, Yu-Xiong Yan, Wei Li, Nan Nan, Jun Zhang, Ya-Nan Ma, Peng-Chao Wang, Xiang-Rui Ma, Shi-Jun Luo, Yong-Chen Xiong
Summary: This article studies the characteristics and properties of hybrid tripartite quantum dot devices, models and analyzes them using the numerical renormalization group method, and proposes unified formulations applicable to different interaction scenarios.
Article
Physics, Multidisciplinary
Luke W. Smith, Hong-Bin Chen, Che-Wei Chang, Chien-Wei Wu, Shun-Tsung Lo, Shih-Hsiang Chao, I Farrer, H. E. Beere, J. P. Griffiths, G. A. C. Jones, D. A. Ritchie, Yueh-Nan Chen, Tse-Ming Chen
Summary: By integrating the Kondo correlation and spin-orbit interactions, researchers have demonstrated electrical control of the Kondo correlation using spin-orbit interactions in semiconductor quantum point contacts. The transition from single to double peak zero-bias anomalies in nonequilibrium transport indicates controlled Kondo spin reversal. Universal scaling of the Kondo conductance suggests that spin-orbit interactions can enhance the Kondo temperature.
PHYSICAL REVIEW LETTERS
(2022)
Article
Nanoscience & Nanotechnology
G. A. Lara, J. P. Ramos-Andrade, D. Zambrano, P. A. Orellana
Summary: In this article, the quantum transport through a single-level quantum dot in the Kondo regime coupled to topological superconductors with Majorana zero modes is investigated. The results show that the presence of Majorana zero modes modifies the Kondo resonance, leading to spin-resolved behavior of the measurable current and differential conductance. This study provides insights into the interplay between the Kondo effect and Majorana zero modes.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2023)
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
Materials Science, Multidisciplinary
Ethan Huecker, Yashar Komijani
Summary: Kondo lattices are classic models of strongly correlated systems, but a full understanding of their excitation spectra is still lacking. Recent progress in engineering heterostructures can be utilized to gain insight into and manipulate these spectra. By using a strong Kondo coupling expansion, we study the spin-1 excitations of one-dimensional and two-dimensional Kondo lattices to investigate whether paramagnons in a Kondo insulator fractionalize into spin-1/2 excitations. Our results can be verified through neutron scattering studies of Kondo-lattice heterostructures and potentially open up new possibilities for engineering strongly correlated electronic systems.
Article
Materials Science, Multidisciplinary
Aleksandr E. Svetogorov, Daniel Loss, Jelena Klinovaja
Summary: We analyze the results of a recent experiment and find that the observed effects are a result of the enhancement of the Kondo effect due to the unusual geometry. We propose that this setup provides a unique and convenient system to study the competition between superconductivity and the Kondo effect, with significant advantages over other approaches.
Article
Materials Science, Multidisciplinary
Anand Manaparambil, Ireneusz Weymann
Summary: We study the nonequilibrium thermoelectric transport properties of a strongly-correlated molecule (or quantum dot) in a tunnel junction. By assuming asymmetric coupling between the molecule and the contacts, we use perturbation theory to determine the nonlinear current driven by voltage and temperature gradients. The subsystem with strong coupling between the molecule and one contact is solved using the numerical renormalization group method, enabling accurate description of Kondo correlations. We investigate the temperature gradient and voltage dependence of the nonlinear and differential Seebeck coefficients, and find that the Kondo correlations cause sign changes in the thermopowers in the Coulomb blockade regime with singly occupied molecule. Furthermore, we analyze the nonlinear heat current and thermoelectric efficiency, showing that the system can function as a heat engine with significant efficiency depending on the transport regime.
Article
Materials Science, Multidisciplinary
V. N. Mantsevich, D. S. Smirnov
Summary: The weak spin-orbit coupling in nonmagnetic semiconductor nanostructures limits the current-induced spin accumulation. However, the Kondo effect provides a possibility to parametrically increase spin polarization. By considering the many-body correlations between a quantum dot and a quantum wire, the current-induced spin accumulation can be enhanced by almost two orders of magnitude at low temperatures, due to the Kondo peak formation and the spin instability caused by strong Coulomb interaction. This effect could be useful for electrically manipulating localized electron spins in quantum dots for quantum applications.
Article
Physics, Multidisciplinary
Chunwei Hsu, Theo A. Costi, David Vogel, Christina Wegeberg, Marcel Mayor, Herre S. J. van der Zant, Pascal Gehring
Summary: Probing the universal low-temperature magnetic field scaling of Kondo-correlated quantum dots via electrical conductance has proven to be experimentally challenging. In this study, we demonstrate how to probe this phenomenon using nonlinear thermocurrent spectroscopy applied to a molecular quantum dot in the Kondo regime. Our findings show that bias-dependent thermocurrent is a sensitive probe of the universal Kondo physics, allowing for direct measurement of the splitting of the Kondo resonance in a magnetic field, and opening up possibilities for investigating nanosystems far from thermal and electrical equilibrium.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Lin Li, Jin-Hua Sun, Wei Su, Zhen-Hua Wang, Dong-Hui Xu, Hong-Gang Luo, Wei-Qiang Chen
Summary: This study investigates the transport behavior of a hybrid superconductor-quantum-dot-superconductor junction, where the interplay between the Kondo effect and the proximity-induced p-wave pairing states is dominant. The Rashba spin-orbit coupling (RSOC) in the semiconductor leads to the creation of spin-triplet pairing components under the proximity-induced superconducting pairing interaction, leading to Zeeman-dependent splitting behaviors of the Yu-Shiba-Rusinov (YSR) state. The Zeeman field from the ferromagnet removes the spin degeneracy of quasiparticles excited in the triplet states, resulting in a phase transition when the ground state is a Kondo singlet.
Article
Physics, Multidisciplinary
Catalin Pascu Moca, Ireneusz Weymann, Miklos Antal Werner, Gergely Zarand
Summary: Magnetic impurities in a metal are screened by the Kondo effect, while in a superconductor they lead to quantum phase transition and subgap states. The Kondo cloud is present in both quantum phases, but complete in the screened phase and only partial in the unscreened phase. The compensation value, related to g factor of impurities, can be monitored experimentally by bias spectroscopy.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Joseph Kleinhenz, Igor Krivenko, Guy Cohen, Emanuel Gull
Summary: This article describes an experiment on the Kondo cloud, where the researchers examined the extent of the cloud in 1D by measuring the effect of nearby electrostatic perturbations on T-K. They also observed the Kondo state in the local density of states of the leads and made detailed predictions for future experiments.
Article
Materials Science, Multidisciplinary
Yinan Fang, Stefano Chesi, Mahn-Soo Choi
Summary: This study theoretically analyzes a state-of-the-art experimental method using ESR-STM to directly probe spin fluctuations in the Kondo effect, finding that sensitivity is most pronounced for probe spins with transverse magnetic anisotropy.
Article
Materials Science, Multidisciplinary
Dmytro Tarasevych, Andreas Rueckriegel, Savio Keupert, Vasilios Mitsiioannou, Peter Kopietz
Summary: Using the functional renormalization group approach, we investigated the phase diagram of a frustrated quantum spin system and found that considering dynamic spin fluctuations and the renormalization of the four-spin interaction can estimate critical temperatures accurately.
