Perturbatively-perfect many-body transfer

TL;DR

This paper demonstrates that perturbatively perfect quantum state transfer of multiple excitations in a 1D chain is possible under specific conditions related to the system's size, with applications in spin transport and quantum batteries.

Contribution

It reveals conditions for perfect many-body quantum transfer in a 1D chain, extending previous single-excitation transfer results to multiple excitations and different particle types.

Findings

Perfect transfer occurs only for certain wire lengths based on modular arithmetic.

Both bosonic and fermionic excitations can be transferred with high fidelity in the weak-coupling limit.

Applications include spin transport and quantum battery charging.

Abstract

The coherent transfer of excitations between different locations of a quantum many-body system is of primary importance in many research areas, from transport properties in spintronics and atomtronics to quantum state transfer in quantum information processing. We address the transfer of $n>1$ bosonic and fermionic excitations between the edges of a one-dimensional chain modeled by a quadratic hopping Hamiltonian, where the block edges, embodying the sender and the receiver sites, are weakly coupled to the quantum wire. We find that perturbatively perfect coherent transfer is attainable in the weak-coupling limit, for both bosons and fermions, only for certain modular arithmetic equivalence classes of the wire's length. Finally we apply our findings to the transport of spins and the charging of a many-body quantum battery.