6 papers
Spectral Transitions and Singular Continuous Spectrum in A New Family of Quasi-periodic Quantum Walks
Xinyu Yang, Long Li, Qi Zhou
This paper introduces and rigorously analyzes a new class of one-dimensional discrete-time quantum walks whose dynamics are governed by a parametrized family of extended CMV matric…
Observation of Metal-Insulator and Spectral Phase Transitions in Aubry-André-Harper Models
Quan Lin, Christopher Cedzich, Qi Zhou +1
Non-Hermitian extensions of the Aubry-André-Harper (AAH) model reveal a rich variety of phase transitions arising from the interplay of quasiperiodicity and non-Hermiticity. Despi…
Almost Periodic Solutions of The Cubic Defocusing Nonlinear Schrödinger Equation
Jake Fillman, Long Li, Milivoje LukiÄ +1
This paper addresses the Cauchy problem for the cubic defocusing nonlinear Schrödinger equation (NLS) with almost periodic initial data. We prove that for small analytic quasiperi…
Cantor spectrum for multidimensional quasi-periodic Schrödinger operators
Bernard Helffer, Qinghui Liu, Yanhui Qu +1
In this paper, we investigate the spectrum of a class of multidimensional quasi-periodic Schrödinger operators that exhibit a Cantor spectrum, which provides a resolution to a que…
Phase Transitions in Quasi-Periodically Driven Quantum Critical Systems: Analytical Results
Jiyuan Fang, Qi Zhou, Xueda Wen
In this work, we study analytically the phase transitions in quasi-periodically driven one dimensional quantum critical systems that are described by conformal field theories (CFTs…
Recovering dark states by non-Hermiticity
Qi Zhou
Dark states, which are incapable of absorbing and emitting light, have been widely applied in multiple disciplines of physics. However, the existence of dark states relies on certa…