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Related papers: Hartman effect from layered $PT$-symmetric system

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We study the tunneling time of Dirac fermions in graphene magnetic barrier through an electrostatic potential and a mass term. This latter generates an energy gap in the spectrum and therefore affects the proprieties of tunneling of the…

Mesoscale and Nanoscale Physics · Physics 2021-09-15 Youssef Fattasse , Miloud Mekkaoui , Ahmed Jellal , Abdelhadi Bahaoui

Since the spatially extended periodic parity-time (PT) symmetric potential can possess certain unique properties compared to a single PT cell (with only a pair of coupled gain-loss components), various schemes have been proposed to realize…

The mechanism of coherent destruction of tunneling found by Grossmann et al. [Phys. Rev. Lett. 67, 516 (1991)] is studied from the viewpoint of quantum optics by considering the photon statistics of a single mode cavity field which is…

Condensed Matter · Physics 2016-08-31 Peter Neu , Robert J. Silbey

A simple model of a quantum clock is applied to the old and controversial problem of how long a particle takes to tunnel through a quantum barrier. The model I employ has the advantage of yielding sensible results for energy eigenstates,…

Quantum Physics · Physics 2009-11-10 P. C. W. Davies

A class of above-barrier quantum-scattering problems is shown to provide an experimentally-accessible platform for studying $\mathcal{PT}$-symmetric Schr\"odinger equations that exhibit spontaneous $\mathcal{PT}$ symmetry breaking despite…

Quantum Physics · Physics 2023-09-12 Micheline B. Soley , Carl M. Bender , A. Douglas Stone

The analytical continuation of classical equations of motion to complex times suggests that a tunnelling particle spends in the barrier an imaginary duration $i|\mathcal T|$. Does this mean that it takes a finite time to tunnel, or should…

Quantum Physics · Physics 2024-05-28 Anton Uranga , Elena Akhmatskaya , Dmitri Sokolovski

Parity-Time (PT) symmetric quantum mechanics is a complex extension of conventional Hermitian quantum mechanics in which physical observables possess a real eigenvalue spectrum. However, an experimental demonstration of the true quantum…

I will provide a pedagogical introduction to non-Hermitian quantum systems that are PT-symmetric, that is they are left invariant under a simultaneous parity transformation (P) and time-reversal (T). I will explain how generalised versions…

Quantum Physics · Physics 2023-02-27 Andreas Fring

In this paper we introduce Parity-Time ($\cal PT$) symmetric perturbation to a one-dimensional Lieb lattice, which is otherwise $\cal P$-symmetric and has a flat band. In the flat band there are a multitude of degenerate dark states, and…

Optics · Physics 2016-01-25 Li Ge

In this paper we study the tunneling using a background independent (polymer) quantization scheme. We show that at low energies, for the tunneling through a single potential barrier, the polymer transmission coefficient and the polymer…

Quantum Physics · Physics 2014-08-29 A. Martín-Ruiz , E. Chan-López , A. Carbajal-Domínguez , J. Bernal

We consider parity-time ($\mathcal{PT}$) symmetric arrays formed by $N$ optical waveguides with gain and $N$ waveguides with loss. When the gain-loss coefficient exceeds a critical value $\gamma_c$, the $\mathcal{PT}$-symmetry becomes…

Optics · Physics 2015-06-17 I V Barashenkov , L Baker , N V Alexeeva

For the relativistic tunneling effect described using Dirac's equation, in [Phys. Rev. A 70, 052112 (2004)] the authors presented the deduction of a general result that allows for the determination of the phase time (group delay) as the sum…

Quantum Physics · Physics 2023-08-24 Said Lantigua , Jonas Maziero

Scattering on the ${\cal PT}$-symmetric Coulomb potential is studied along a U-shaped trajectory circumventing the origin in the complex $x$ plane from below. This trajectory reflects ${\cal PT}$ symmetry, sets the appropriate boundary…

Quantum Physics · Physics 2009-07-01 Geza Levai , Petr Siegl , Miloslav Znojil

The measurement of the tunneling time (T-time) in today's attosecond and strong field (low-frequency) experiments, despite its controversial discussion, offers a fruitful opportunity to understand time measurement and the time in quantum…

Quantum Physics · Physics 2017-01-19 Ossama Kullie

Tunneling is an important physical process. The observation that particles surmount a high mountain in spite of the fact that they don't have the necessary energy cannot be explained by classical physics. However, this so called tunneling…

Quantum Physics · Physics 2009-11-13 G. Nimtz , A. A. Stahlhofen

The $\mathcal{PT}$ symmetry breaking threshold in discrete realizations of systems with balanced gain and loss is determined by the effective coupling between the gain and loss sites. In one dimensional chains, this threshold is maximum…

Quantum Physics · Physics 2018-04-13 Kaustubh S. Agarwal , Rajeev K. Pathak , Yogesh N. Joglekar

The Hamiltonian for a PT-symmetric chain of coupled oscillators is constructed. It is shown that if the loss-gain parameter $\gamma$ is uniform for all oscillators, then as the number of oscillators increases, the region of unbroken…

Mathematical Physics · Physics 2014-08-27 Carl M. Bender , Mariagiovanna Gianfreda , S. P. Klevansky

Quantum particles interacting with potential barriers are ubiquitous in physics, and the question of how much time they spend inside classically forbidden regions has attracted interest for many decades. Recent developments of new…

Quantum Physics · Physics 2021-07-06 Seyedmohammad Yusofsani , Miroslav Kolesik

Non-Hermitian PT-symmetric quantum-mechanical Hamiltonians generally exhibit a phase transition that separates two parametric regions, (i) a region of unbroken PT symmetry in which the eigenvalues are all real, and (ii) a region of broken…

Quantum Physics · Physics 2012-10-11 Carl M. Bender , David J. Weir

We study transport properties of an array created by alternating $(a,b)$ layers with balanced loss/gain characterized by the key parameter $\gamma$. It is shown that for non-equal widths of $(a,b)$ layers, i.e., when the corresponding…