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arXiv · 1302.4314

PT symmetric lattices with a local degree of freedom

Harsha Vemuri·Yogesh N. Joglekar
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Abstract

Recently, open systems with balanced, spatially separated loss and gain have been realized and studied using non-Hermitian Hamiltonians that are invariant under the combined parity and time-reversal ($\mathcal{PT}$) operations. Here, we model and investigate the effects of a local, two-state, quantum degree of freedom, called a pseudospin, on a one-dimensional tight-binding lattice with position-dependent tunneling amplitudes and a single pair of non-Hermitian, $\mathcal{PT}$-symmetric impurities. We show that if the resulting Hamiltonian is invariant under exchange of two pseudospin labels, the system can be decomposed into two uncoupled systems with tunable threshold for $\mathcal{PT}$ symmetry breaking. We discuss implications of our results to systems with specific tunneling profiles, and open or periodic boundary conditions.

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Harsha Vemuri, Yogesh N. Joglekar. 2013-02-18. PT symmetric lattices with a local degree of freedom. https://doi.org/10.1103/physreva.87.044101

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