Non-Hermitian Hamiltonians with unitary and antiunitary symmetries

We analyse several non-Hermitian Hamiltonians with antiunitary symmetry from the point of view of their point-group symmetry. It enables us to predict the degeneracy of the energy levels and to reduce the dimension of the matrices necessary for the diagonalization of the Hamiltonian in a given basis...

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Bibliographic Details
Authors: Fernández, Francisco Marcelo, Garcia, Javier
Format: article
Status:Published version
Publication Date:2014
Country:Argentina
Institution:Consejo Nacional de Investigaciones Científicas y Técnicas
Repository:CONICET Digital (CONICET)
Language:English
OAI Identifier:oai:ri.conicet.gov.ar:11336/32199
Online Access:http://hdl.handle.net/11336/32199
Access Level:Open access
Keyword:Pt-Symmetry
Multidimensional Oscillator
Point-Group Symmetry
Pt Phase Transition
Broken Pt Symmetry
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Description
Summary:We analyse several non-Hermitian Hamiltonians with antiunitary symmetry from the point of view of their point-group symmetry. It enables us to predict the degeneracy of the energy levels and to reduce the dimension of the matrices necessary for the diagonalization of the Hamiltonian in a given basis set. We can also classify the solutions according to the irreducible representations of the point group and thus analyse their properties separately. One of the main results of this paper is that some PT-symmetric Hamiltonians with point-group symmetry C2v exhibit complex eigenvalues for all values of a potential parameter. In such cases the PT phase transition takes place at the trivial Hermitian limit which suggests that the phenomenon is not robust. Point-group symmetry enables us to explain such anomalous behaviour and to choose a suitable antiunitary operator for the PT symmetry.