Claudio ContiNon-commutative dynamics, symmetry breaking, and entanglement in quantum walks.
https://arxiv.org/abs/2412.02429
#physics #topology #quantumphysics #nonabelian
Non-Abelian evolution is a landmark in modern theoretical physics. However, whether non-commutative dynamics significantly impact the control of entanglement and transport in quantum systems is an open question. We propose to utilize non-Abelian Thouless pumping in one-dimensional discrete-time quantum walks in lattices with degenerate Bloch bands. We show how the interplay of non-commutativity and topology enables geometrically protected quantum coins and shift operators. Different classes of tunable protected quantum walks arise by composing different non-Abelian pumping cycles. Surprisingly, the walks break parity symmetry and generate a dynamic process described by a Weyl-like equation. The amount of entanglement can be varied by acting on the initial conditions. The asymptotic statistical distribution and features are determined by closed-form analytical expressions and confirmed numerically.
Thouless quantum walks in topological flat bands
Non-Abelian gauge symmetries are cornerstones of modern theoretical physics, underlying fundamental interactions and the geometric structure of quantum mechanics. However, their potential to control quantum coherence, entangle- ment, and transport in engineered quantum systems remains to a large extent unexplored. In this work, we propose utilizing non-Abelian Thouless pumping to realize one-dimensional discrete-time quantum walks on topological lattices char- acterized by degenerate flat bands. Through carefully designed pumping cycles, we implement different classes of holonomic coin and shift operators. This frame- work allows for the construction of quantum walks that encode the topological and geometric properties of the underlying system. Remarkably, the resulting evolution exhibits parity symmetry breaking and gives rise to a dynamical pro- cess governed by a Weyl-like equation, highlighting the deep connection between parity and time-reversal symmetry breaking in the system.
Quantum Observer
xameer