Coexistence of directed momentum current and ballistic energy diffusion in coupled non-Hermitian kicked rotors

Abstract

We numerically investigate the quantum transport in a coupled kicked rotors with the $\mathcal{P}\mathcal{T}$-symmetric potential. We find that the spontaneous $\mathcal{P}\mathcal{T}$-symmetry breaking of wavefunctions emerges when the amplitude of the imaginary part of the complex potential is beyond a threshold value, which can be modulated by the coupling strength effectively. In the regime of the $\mathcal{P}\mathcal{T}$-symmetry breaking, the particles driven by the periodical kicks move unidirectionally in momentum space, indicating the emergence of a directed current. Meanwhile, with increasing the coupling strength, we find a transition from the ballistic energy diffusion to a kind of the modified ballistic energy diffusion where the width of the wavepacket also increases with time in a power law. Our findings suggest that the decoherence effect induced by the interplay between the inter-particle coupling and the non-Hermitian driving potential is responsible for these particular transport behaviors.

8 pages, 7 figures

References in corpus (26)

• Cold atoms in cavity-generated dynamical optical potentials
• PT-Symmetric Wave Chaos
• Quantized Adiabatic Transport in Momentum Space
• Ballistic spin transport in a periodically driven integrable quantum system
• Phase transitions in a non-Hermitian Aubry-André-Harper model
• Linear entropy as an entanglement measure in two-fermion systems
• Stability of superdiffusion in nearly integrable spin chains
• Omnidirectional Transport in Fully Reconfigurable Two Dimensional Optical Ratchets
• Dynamical evolution in a one-dimensional incommensurate lattice with $\mathcal{P}\mathcal{T}$ symmetry
• Interaction-driven breakdown of dynamical localization in a kicked quantum gas
• Conservative chaotic map as a model of quantum many-body environment
• Defective Majorana zero modes in non-Hermitian Kitaev chain
• Planck's quantum-driven integer quantum Hall effect in chaos
• Localization, quantum resonances and ratchet acceleration in a periodically-kicked $\mathcal{P}\mathcal{T}$-symmetric quantum rotator
• Prethermalization and Thermalization in Periodically-Driven Many-Body Systems away from the High-Frequency Limit
• The ratchet effect and the transporting islands in the chaotic sea
• Directed momentum current induced by the PT-symmetric driving
• Lyapunov spectrum scaling for classical many-body dynamics close to integrability
• Effective thermalization of a many-body dynamically localized Bose gas
• Super-exponential diffusion in nonlinear non-Hermitian systems
• Dynamical localization of interacting bosons in the few-body limit
• Effective protection of quantum coherence by non-Hermitian driving
• Quantum and Classical Superballistic Transport in a Relativistic Kicked-Rotor System
• The Gross Pitaevski map as a chaotic dynamical system
• Directed transport and Floquet analysis for a periodically kicked wavepacket at a quantum resonance
• Subdiffusion in wave packets with periodically kicked interactions