We investigate the spectral properties and dynamical features of a time-periodic PT -symmetric Hamiltonian on a one-dimensional tight-binding lattice. Our analysis shows that a high-frequency modulation can drive the system under a transition between the broken-PT and the unbroken-PT phases. Interestingly, the time-periodic modulation in the unbroken-PT regime results in novel spectral features and transport behavior, with no counterpart in Hermi- tian time-periodic lattices. In particular, a significant broadening of the quasi-energy spectrum is predicted, leading to a hyper-ballistic transport regime. Also, near the PT -symmetry break- ing the dispersion curve of the lattice band becomes linear, with a strong reduction of quantum wave packet spreading.
A time-periodic PT -symmetric tight-binding lattice Hamiltonian: spectral properties and transport features
DELLA VALLE, GIUSEPPE;LONGHI, STEFANO
2013-01-01
Abstract
We investigate the spectral properties and dynamical features of a time-periodic PT -symmetric Hamiltonian on a one-dimensional tight-binding lattice. Our analysis shows that a high-frequency modulation can drive the system under a transition between the broken-PT and the unbroken-PT phases. Interestingly, the time-periodic modulation in the unbroken-PT regime results in novel spectral features and transport behavior, with no counterpart in Hermi- tian time-periodic lattices. In particular, a significant broadening of the quasi-energy spectrum is predicted, leading to a hyper-ballistic transport regime. Also, near the PT -symmetry break- ing the dispersion curve of the lattice band becomes linear, with a strong reduction of quantum wave packet spreading.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
