Transport, shot noise, and topology in AC-driven dimer arrays

Abstract

We analyze an AC-driven dimer chain connected to a strongly biased electron source and drain. It turns out that the resulting transport exhibits fingerprints of topology. They are particularly visible in the driving-induced current suppression and the Fano factor. Thus, shot noise measurements provide a topological phase diagram as a function of the driving parameters. The observed phenomena can be explained physically by a mapping to an effective time-independent Hamiltonian and the emergence of edge states. Moreover, by considering quantum dissipation, we determine the requirements for the coherence properties in a possible experimental realization. For the computation of the zero-frequency noise, we develop an efficient method based on matrix-continued fractions.

Robustness of symmetry-protected topological states against time-periodic perturbations

“…( 1)] has chiral symmetry, implying the existence of a unitary operator Γ such that ΓH 0 Γ = −H 0 where Γc A,j Γ = c A,j and Γc B,j Γ = −c B,j . The representation [28] Γ ≡ e iπ j c † B,j c B,j…”

Simulation of 1D Topological Phases in Driven Quantum Dot Arrays

“…Consequently, a great effort is being made to simulate the behaviour of TIs by tailoring other quantum systems, whose properties can be more easily controlled. Within this context, timedependent modulations have proven to be useful tools to modify the topology [4][5][6][7][8][9][10][11][12][13][14][15]. Particularly, they have been used to simulate the so-called "Floquet topological insulators" (FTIs) [16][17][18] upon different systems .…”

“…Typically, other driving protocols have been considered in the literature, such as sinusoidal driving fields f (t) = sin(ωt + φ) [8,10,11,27], or standing waves f (t) = cos(ωt) N j=1 cos(kx j + φ) [73]. However, none of them would be suitable for engineering arbitrary chiral topological phases.…”

Quantum dot coupled to topological insulators: The role of edge states

“…Apart from the original polymer system, the SSH model was realized experimentally and the topological edge states were detected in more controllable settings such as cold atoms [20][21][22][23], electronic states in artificial atomic lattices [24] or superlattices [25], mechanical chains [26], and photonic systems [27][28][29]. Among theoretically predicted signatures of the topological edge states are effects in the entanglement entropy [30], in the decoherence of a coupled qubit [31], and in transport and noise characteristics in non-equilibrium settings where a current is driven through an SSH chain [32][33][34][35][36]. However, to the best of our knowledge, the archetypal mesoscopic setup of a quantum dot coupled to leads has not yet been studied if the latter are modeled as SSH chains.…”