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A non-hermitian deformation of the one-dimensional transverse Ising model is shown to have the property of quasi-hermiticity. The transverse Ising chain is obtained from the starting non-hermitian Hamiltonian through a similarity…

Statistical Mechanics · Physics 2009-11-09 Tetsuo Deguchi , Pijush K. Ghosh

Quantum canonical transformations of the second kind and the non-Hermitian realizations of the basic canonical commutation relations are investigated with a special interest in the generalization of the conventional ladder operators. The…

High Energy Physics - Theory · Physics 2009-10-28 W. S. l'Yi

A non-commuting measurement transfers, via the apparatus, information encoded in a system's state to the external "observer". Classical measurements determine properties of physical objects. In the quantum realm, the very same notion…

Quantum Physics · Physics 2016-08-31 Bartłomiej Gardas , Sebastian Deffner , Avadh Saxena

Simple examples of non-Hermitian Hamiltonians with purely real spectra defined in $L^2(R^+)$ having spectral singularities inside the continuous spectrum are given. It is shown that such Hamiltonians may appear by shifting the ndependent…

Quantum Physics · Physics 2009-11-11 Boris F Samsonov

The {\eta} pseudo PT symmetry theory, denoted by the symbol {\eta}, explores the conditions under which non-Hermitian Hamiltonians can possess real spectra despite the violation of PT symmetry, that is the adjoint of H, denoted H^{{\dag}}…

Quantum Physics · Physics 2024-01-09 Mustapha Maamache , Nour El Houda Absi

We notice that PT symmetric non-Hermitian one dimensional simple Harmonic Oscillator under simultaneous transformation of co-ordinate and momentum with proper choice of positive oscillating frequency can reflect negative spectrum with well…

Quantum Physics · Physics 2018-03-19 Biswanath Rath

Over the past decade classical optical systems with gain or loss, modelled by non-Hermitian parity-time symmetric Hamiltonians, have been deeply investigated. Yet, their applicability to the quantum domain with number-resolved photonic…

Quantum Physics · Physics 2024-05-15 Ross Wakefield , Anthony Laing , Yogesh N. Joglekar

A class of pseudo-hermitian quantum system with an explicit form of the positive-definite metric in the Hilbert space is presented. The general method involves a realization of the basic canonical commutation relations defining the quantum…

Quantum Physics · Physics 2010-03-15 Pijush K. Ghosh

The harmonic oscillator Hamiltonian, when augmented by a non-Hermitian $\cal{PT}$-symmetric part, can be transformed into a Hermitian Hamiltonian. This is achieved by introducing a metric which, in general, renders other observables such as…

Quantum Physics · Physics 2007-05-23 D. P. Musumbu , H. B. Geyer , W. D. Heiss

Recently (see quant-ph/0503040) an explicit example has been given of a PT-symmetric non-diagonalizable Hamiltonian. In this paper we show that such Hamiltonians appear as supersymmetric (SUSY) partners of Hermitian (hence diagonalizable)…

Quantum Physics · Physics 2009-11-11 B F Samsonov

We prove that any symmetric Hamiltonian that is a quadratic function of the coordinates and momenta has a pseudo-Hermitian adjoint or regular matrix representation. The eigenvalues of the latter matrix are the natural frequencies of the…

Quantum Physics · Physics 2016-05-04 Francisco M Fernández

We consider a two-parameter non hermitean quantum-mechanical hamiltonian that is invariant under the combined effects of parity and time reversal transformation. Numerical investigation shows that for some values of the potential parameters…

Quantum Physics · Physics 2009-10-31 F. M. Fernandez , R. Guardiola , J. Ros , M. Znojil

The family of metric operators, constructed by Musumbu {\sl et al} (2007 {\sl J. Phys. A: Math. Theor.} {\bf 40} F75), for a harmonic oscillator Hamiltonian augmented by a non-Hermitian $\cal PT$-symmetric part, is re-examined in the light…

Mathematical Physics · Physics 2009-11-13 C. Quesne

A re-formulated, non-Hermitian version of the Witten's supersymmetric quantum mechanics is presented. Its use of pseudo-Hermitian (so called PT symmetric) Hamiltonians is reviewed and illustrated via several forms of an innovated…

High Energy Physics - Theory · Physics 2007-05-23 Miloslav Znojil

Quantum theory can be formulated with certain non-Hermitian Hamiltonians. An anti-linear involution, denoted by PT, is a symmetry of such Hamiltonians. In the PT-symmetric regime the non-Hermitian Hamiltonian is related to a Hermitian one…

High Energy Physics - Theory · Physics 2020-10-02 Daniel Areán , Karl Landsteiner , Ignacio Salazar Landea

A non-Hermitian generalized oscillator model, generally known as the Swanson model, has been studied in the framework of R-deformed Heisenberg algebra. The non-Hermitian Hamiltonian is diagonalized by generalized Bogoliubov transformation.…

Mathematical Physics · Physics 2015-06-12 Rajkumar Roychoudhury , Barnana Roy , Partha Pratim Dube

An approximate method is suggested to obtain analytical expressions for the eigenvalues and eigenfunctions of the some quantum optical models. The method is based on the Lie-type transformation of the Hamiltonians. In a particular case it…

Quantum Physics · Physics 2009-11-11 Ramazan Koc

It is shown that the radial part of the Hydrogen Hamiltonian factorizes as the product of two not mutually adjoint first order differential operators plus a complex constant epsilon. The 1-susy approach is used to construct non-hermitian…

Quantum Physics · Physics 2011-09-21 Oscar Rosas-Ortiz , Rodrigo Munoz

When a non-hermitian hamiltonian has a certain symmetry, such as the PT pseudo-hermiticity, it is still possible that the hamiltonian has a real spectrum. In this note, by adding an imaginary potential proportional to ip_1p_2 to the…

Quantum Physics · Physics 2011-10-12 Jun-Qing Li , Yan-Gang Miao

We show how, given a non-Hermitian Hamiltonian $H$, we can generate new non-Hermitian operators sequentially, producing a virtually infinite chain of non-Hermitian Hamiltonians which are isospectral to $H$ and $H^\dagger$ and whose…

Mathematical Physics · Physics 2021-06-30 Fabio Bagarello , Naomichi Hatano