Floquet engineering of continuous-time quantum walks: towards the simulation of complex and next-to-nearest neighbor couplings

Novo, Leonardo; Ribeiro, Sofia

doi:10.48550/arxiv.2012.00448

Cited by 1 publication

(3 citation statements)

References 51 publications

(113 reference statements)

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“…In this work, we generalize the study to address the problem of the long time dynamics of a single particle walk on a one-dimensional spatial lattice with complex hopping amplitudes. It is of considerable interest to extend the study to the case of complex hopping amplitudes, since it is known that complex hopping strengths break time-reversal symmetry and can lead to novel effects like chiral propagation [27][28][29]. Recent work [29] suggested protocols through Floquet engineering realizing a quantum walk with complex hopping amplitudes.…”

Section: Introductionmentioning

confidence: 99%

“…It is of considerable interest to extend the study to the case of complex hopping amplitudes, since it is known that complex hopping strengths break time-reversal symmetry and can lead to novel effects like chiral propagation [27][28][29]. Recent work [29] suggested protocols through Floquet engineering realizing a quantum walk with complex hopping amplitudes. The study of chiral walks is also of interest because they allow for controlled information transfer in quantum systems and directional biasing without a biased initial state [27][28][29].…”

Section: Introductionmentioning

confidence: 99%

“…Recent work [29] suggested protocols through Floquet engineering realizing a quantum walk with complex hopping amplitudes. The study of chiral walks is also of interest because they allow for controlled information transfer in quantum systems and directional biasing without a biased initial state [27][28][29]. Effect of time reversal symmetry breaking has been demonstrated in case of triangular chains showing enhancement of quantum transport whereas in case of loops there is complete suppression [27,28].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Long time dynamics of a single particle extended quantum walk on a one dimensional lattice with complex hoppings: a generalized hydrodynamic description

Bhandari¹,

Durganandini²

2021

Preprint

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We study the continuous-time quantum walk of a single particle (initially localized at a single site) on a one-dimensional spatial lattice with real nearest neighbour and complex next-nearest neighbour hopping amplitudes. Complex couplings lead to chiral propagation and a causal cone structure asymmetric about the origin. We provide a hydrodynamic description for quantum walk dynamics in large space time limit. We find a global "quasi-stationary state" which can be described in terms of the local quasi-particle densities satisfying Euler type of hydrodynamic equation and is characterized by an infinite set of conservation laws satisfied by scaled cumulative position moments. Further, we show that there is anomalous sub-diffusive scaling near the extremal fronts, which can be described by higher order hydrodynamic equations. The long time behaviour for any complex next nearest neighbour hopping with a non-zero real component is similar to that of purely real hopping (apart from asymmetric distribution). There is a critical coupling strength at which there is a Lifshitz transition where the topology of the causal structure changes from a regime with one causal cone to a regime with two nested causal cones. On the other hand, for purely imaginary next-nearest neighbour hopping, there is a transition from one causal cone to a regime with two partially overlapping cones due to the existence of degenerate maximal fronts (moving with the same maximal velocity). The nature of the Lifshitz transition and the scaling behaviour (both) at the critical coupling strength is different in the two cases.

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