Interband coherence induced correction to Thouless pumping: possible observation in cold-atom systems

Abstract

In Thouless pump, the charge transport in a one-dimensional insulator over an adiabatic cycle is topologically quantized. For nonequilibrium initial states, however, interband coherence will induce a previously unknown contribution to Thouless pumping. Though not geometric in nature, this contribution is independent of the time scale of the pumping protocol. In this work, we perform a detailed analysis of our previous finding [Phys. Rev. B 91, 085420 (2015)] in an already available cold-atom setup. We show that initial states with interband coherence can be obtained via a quench of the system's Hamiltonian. Adiabatic pumping in the post-quench system are then examined both theoretically and numerically, in which the interband coherence is shown to play an important role and can hence be observed experimentally. By choosing adiabatic protocols with different switching-on speeds, we also show that the contribution of interband coherence to adiabatic pumping can be tuned. It is further proposed that the interband coherence induced correction to Thouless pumping may be useful in capturing a topological phase transition point. All our results have direct experimental interests.

18 pages, 5 figures

References in corpus (16)

• Photovoltaic Hall effect in graphene
• Topological Acoustics
• Topological characterization of periodically-driven quantum systems
• Observation of phononic helical edge states in a mechanical 'topological insulator'
• Irradiated graphene as a tunable Floquet topological insulator
• Photoinduced transition between conventional and topological insulators in two-dimensional electronic systems
• Multiterminal Conductance of a Floquet Topological Insulator
• Modulated Floquet Topological Insulators
• Topological index for periodically driven time-reversal invariant 2D systems
• Quantized Adiabatic Transport in Momentum Space
• Fate of Majorana fermions and Chern numbers after a quantum quench
• Aspects of Floquet Bands and Topological Phase Transitions in a Continuously Driven Superlattice
• Dynamical topological phases in quenched spin-orbit coupled degenerate Fermi gas
• Non-equilibrium Fractional Hall Response After a Topological Quench
• Interband Coherence Induced Correction to Adiabatic Pumping in Periodically Driven Systems
• Topological phase transition in the quench dynamics of a one-dimensional Fermi gas