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Related papers: Enhancement of persistent current in a non-Hermiti…

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An interacting quantum dot inserted in a mesoscopic ring is investigated. A variational ansatz is employed to describe the ground state of the system in the presence of the Aharonov-Bohm flux. It is shown that, for even number of electrons…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Kicheon Kang , Sung-Chul Shin

Measurements of elastic and inelastic cotunneling currents are presented on a two-terminal Aharonov--Bohm interferometer with a Coulomb blockaded quantum dot embedded in each arm. Coherent current contributions, even in magnetic field, are…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Martin Sigrist , Thomas Ihn , Klaus Ensslin , Matthias Reinwald , Werner Wegscheider

Majorana fermions act as their own antiparticle, and they have long been thought to be confined to the realm of pure theory. However, interest in them has recently resurfaced, as it was realized through the work of Kitaev that some…

Mesoscale and Nanoscale Physics · Physics 2021-08-16 T. C. Bartolo , J. S. Smith , B. Muralidharan , C. Müller , T. M. Stace , J. H. Cole

The antiferromagnet is a closed Hermitian system, we find that its excitations, even in the absence of dissipation, can be viewed as a non-Hermitian system with dissipative coupling. Consequently, the antiferromagnetic resonance spectrum…

Mesoscale and Nanoscale Physics · Physics 2021-11-19 Yutian Wang , Jiang Xiao

We investigate equilibrium (background), linear, and nonlinear spin currents in two-dimensional Rashba spin-orbit coupled altermagnet systems, using a modified spin current operator that includes anomalous velocity from non-zero Berry…

Mesoscale and Nanoscale Physics · Physics 2025-10-17 Priyadarshini Kapri

The persistent currents driven by the pure Aharonov-Bohm type magnetic field in mesoscopic normal metal or semiconducting cylinders are studied. A two-dimensional (2D) Fermi surfaces are characterized by four parameters. Several conditions…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 M. Stebelski , M. Szopa , E. Zipper

Non-Hermitian Hamiltonians provide an alternative perspective on the dynamics of quantum and classical systems coupled non-conservatively to an environment. Once primarily an interest of mathematical physicists, the theory of non-Hermitian…

Mesoscale and Nanoscale Physics · Physics 2022-12-20 Hilary M. Hurst , Benedetta Flebus

In this paper, we consider a massive charged fermionic quantum field and investigate the current densities induced by a magnetic flux running along the core of an idealized cosmic string in the background geometry of a 5-dimensional anti-de…

High Energy Physics - Theory · Physics 2020-11-17 S. Bellucci , W. Oliveira dos Santos , E. R. Bezerra de Mello

We have computed persistent currents in a disordered mesoscopic ring in the presence of small electron-electron interactions, treated in first order perturbation theory. We have investigated both a contact (Hubbard) and a nearest neighbour…

Condensed Matter · Physics 2009-10-22 Michel Ramin , Bertrand Reulet , Helene Bouchiat

Dissipation in open systems enriches the possible symmetries of the Hamiltonians beyond the Hermitian framework allowing the possibility of novel non-Hermitian topological phases, which exhibit long-living end states that are protected…

Quantum Physics · Physics 2023-04-05 Wojciech Brzezicki , Matti Silveri , Marcin Płodzień , Francesco Massel , Timo Hyart

We employ the Hartree-Fock approximation to identify the magnetic ground state of the Hubbard model on a frustrated square lattice. We investigate the phase diagram as a function of the Coulomb repulsion's strength $U$, and the ratio $t'/t$…

Strongly Correlated Electrons · Physics 2020-11-18 Yun-Peng Huang , Jin-Wei Dong , Panagiotis Kotetes , Sen Zhou

The geometrical Berry phase is key to understanding the behaviour of quantum states under cyclic adiabatic evolution. When generalised to non-Hermitian systems with gain and loss, the Berry phase can become complex, and should modify not…

Mesoscale and Nanoscale Physics · Physics 2022-05-06 Yaashnaa Singhal , Enrico Martello , Shraddha Agrawal , Tomoki Ozawa , Hannah Price , Bryce Gadway

The ordinary time-dependent perturbation theory of quantum mechanics, that describes the interaction of a stationary system with a time-dependent perturbation, predicts that the transition probabilities induced by the perturbation are…

Quantum Physics · Physics 2017-10-11 S. Longhi , G. Della Valle

We explore the unconventional wave scattering properties of non-Hermitian systems in which amplification or damping are induced by time-periodic modulation. These non- Hermitian time-Floquet systems are capable of non-reciprocal operations…

Mesoscale and Nanoscale Physics · Physics 2018-02-28 Theodoros T. Koutserimpas , Romain Fleury

We consider an efficient scheme to simulate fermionic Hubbard models with nonlocal density-density interactions in two dimensions, based on bond-centered auxiliary-field quantum Monte Carlo. The simulations are shown to be sign-problem free…

Strongly Correlated Electrons · Physics 2015-12-09 Michael Golor , Stefan Wessel

Asymmetric coupling amplitudes effectively create an imaginary gauge field, which induces a non-Hermitian Aharonov-Bohm (AB) effect. Nonzero imaginary magnetic flux invalidates the bulk-boundary correspondence and leads to a topological…

Mesoscale and Nanoscale Physics · Physics 2019-02-06 L. Jin , Z. Song

We review recent progress in our theoretical understanding of strongly correlated fermion systems in the presence of disorder. Results were obtained by the application of a powerful nonperturbative approach, the Dynamical Mean-Field Theory…

Strongly Correlated Electrons · Physics 2015-05-18 K. Byczuk , W. Hofstetter , D. Vollhardt

We uncover a disorder-driven instability in the diffusive Fermi liquid phase of a class of many-fermion systems, indicative of a metal-insulator transition of first order type, which arises solely from the competition between quenched…

Disordered Systems and Neural Networks · Physics 2009-11-13 Matthew S. Foster , Andreas W. W. Ludwig

The model of a ring threaded by the Aharonov-Bohm flux underlies our understanding of a coupling between gauge potentials and matter. The typical formulation of the model is based upon a single particle picture, and should be extended when…

Quantum Gases · Physics 2023-08-29 Fabian Brauneis , Areg Ghazaryan , Hans-Werner Hammer , Artem G. Volosniev

The interplay among topology, disorder, and non-Hermiticity can induce some exotic topological and localization phenomena. Here we investigate this interplay in a two-dimensional non-Hermitian disordered Chern-insulator model with two…

Mesoscale and Nanoscale Physics · Physics 2020-06-11 Ling-Zhi Tang , Ling-Feng Zhang , Guo-Qing Zhang , Dan-Wei Zhang