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Related papers: Non-Hermitian quantum rings

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The manipulation of single magnetic molecules may enable new strategies for high-density information storage and quantum-state control. However, progress in these areas depends on developing techniques for addressing individual molecules…

By measuring electron tunneling between a ferromagnet and individual energy levels in an aluminum quantum dot, we show how spin-resolved quantum states can be used as filters to determine spin-dependent tunneling rates. We also observe…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Mandar M. Deshmukh , D. C. Ralph

It is well known that a particle in a periodic potential with an additional constant force performs Bloch oscillations. Modulating every second period of the potential, the original Bloch band splits into two subbands. The dynamics of…

Quantum Physics · Physics 2007-05-23 B. M. Breid , D. Witthaut , H. J. Korsch

Non-classical states that are characterized by their non-positive quasi-probabilities in phase space are known to be the basis for various quantum effects. In this work, we investigate the interrelation between the non-classicality and…

Quantum Physics · Physics 2010-10-12 Kisik Kim , Jaewan Kim , Joonwoo Bae

In this work, we investigate the behavior of non-relativistic quantum particles immersed in a cosmic string space-time background. Our study involves the examination of these particles as they interact with a range of influences, including…

Quantum Physics · Physics 2024-05-29 Faizuddin Ahmed , Allan R. P. Moreira

The evolution of the quantum wave packet describing an atom trapped in the surface-tip junction of the scanning tunneling microscope is investigated by using the time-dependent Schroedinger equation, and by a quasi-classical Hamiltonian…

Quantum Physics · Physics 2008-02-21 M. Grigorescu

A constructive theoretical platform for the description of quantum space-time crystals uncovers for $N$ interacting and ring-confined rotating particles the existence of low-lying states with proper space-time crystal behavior. The…

Quantum Gases · Physics 2017-10-18 Constantine Yannouleas , Uzi Landman

It is known that the appearance of Klein tunneling in graphene makes it hard to keep or localize electrons in a graphene-based quantum dot (GQD). However, a magnetic field can be used to temporarily confine an electron that is traveling…

Mesoscale and Nanoscale Physics · Physics 2023-12-27 Mohammed El Azar , Ahmed Bouhlal , Abdulaziz D. Alhaidari , Ahmed Jellal

We investigate the many-particle and mean-field correspondence for a non-Hermitian N-particle Bose-Hubbard dimer where a complex onsite energy describes an effective decay from one of the modes. Recently a generalized mean-field…

Quantum Physics · Physics 2010-07-22 Eva-Maria Graefe , Hans Jürgen Korsch , Astrid Elisa Niederle

Making use of self-assembly techniques, we demonstrate the realization of nanoscopic semiconductor quantum rings in which the electronic states are in the true quantum limit. We employ two complementary spectroscopic techniques to…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 A. Lorke , R. J. Luyken , A. O. Govorov , J. P. Kotthaus , J. M. Garcia , P. M. Petroff

We report electronic transmission properties of a tight binding Aharonov-Bohm ring threaded by a magnetic flux, to one arm of which a finite cluster of atoms has been attached from one side. we demonstrate that, by suitably choosing the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Supriya Jana , Arunava Chakrabarti

Since the realization of quantum systems described by non-Hermitian Hamiltonians with parity-time (PT) symmetry, interest in non-Hermitian, quantum many-body models has steadily grown. Most studies to-date map to traditional quantum spin…

Quantum Physics · Physics 2023-12-07 Jacob Muldoon , Yogesh N. Joglekar

We analyze spectral properties of a quantum graph in the form of a ring chain with a $\delta$ coupling in the vertices exposed to a homogeneous magnetic field perpendicular to the graph plane. We find the band spectrum in the case when the…

Mathematical Physics · Physics 2019-12-10 Pavel Exner , Stepan S. Manko

The tunnel splitting in biaxial antiferromagnetic particles is studied with a magnetic field applied along the hard anisotropy axis. We observe the oscillation of tunnel splitting as a function of the magnetic field due to the quantum phase…

Condensed Matter · Physics 2019-08-17 Yi-Hang Nie , Yan-Hong Jin , J. -Q. Liang , H. J. W. Müller-Kirsten , D. K. Park , F. -C. Pu

A quantum spin-$\frac{1}{2}$ chain with an axial symmetry is normally described by quasiparticles associated with the spins oriented along the axis of rotation. Kinetic constraints can enrich such a description by setting apart different…

Quantum Physics · Physics 2024-04-25 Maurizio Fagotti

Non-interacting particles in non-Hermitian quasi crystals display localization-delocalization and spectral phase transitions in complex energy plane, that can be characterized by point-gap topology. Here we investigate the spectral and…

Quantum Physics · Physics 2025-04-10 Stefano Longhi

Real-valued band structures are foundational to analyzing periodic systems within the Hermitian description and have been experimentally well-established over recent decades. In contrast, non-Hermitian systems exhibit complex band…

Quantum Physics · Physics 2025-10-24 Jia-Xin Zhong , Jing Lin , Kai Chen , Jing Lu , Kun Ding , Yun Jing

We study theoretically the optical properties of an exciton in a two-dimensional ring threaded by a magnetic flux. We model the quantum ring by a confining potential that can be continuously tuned from strictly one-dimensional to truly…

Mesoscale and Nanoscale Physics · Physics 2011-12-05 C. González-Santander , F. Domínguez-Adame , R. A. Römer

Rarely noted paradoxes and their resolution lead to non-Hermitian behaviors due to boundary terms, even for closed systems and with real potentials. The role played by these non-Hermiticities on quantum mechanical uncertainty relations is…

General Physics · Physics 2021-10-05 K. Moulopoulos

The existence of topological zero modes in nontrivial phase of quantum Ising chain results in not only the Kramers-like degeneracy spectrum, but also dynamic response for non-Hermitian perturbation in the ordered phase (2021 Phys. Rev.…

Quantum Physics · Physics 2022-09-16 K. L. Zhang , Z. Song