Universal Uhrig dynamical decoupling for bosonic systems

TL;DR

This paper introduces a universal dynamical decoupling method for bosonic systems that effectively suppresses decoherence and homogenizes multi-mode systems using a minimal number of Gaussian unitaries and SWAP gates, enabling decoherence-free quantum information encoding.

Contribution

It presents a novel deterministic decoupling scheme for continuous variable systems that achieves high-order decoherence suppression and system homogenization with efficient pulse sequences.

Findings

Suppresses quadratic system-bath interactions to N-th order with N pulses.

Homogenizes multi-mode bosonic systems using polynomially many pulses.

Creates decoherence-free subspaces for quantum information encoding.

Abstract

We construct efficient deterministic dynamical decoupling schemes protecting continuous variable degrees of freedom. Our schemes target decoherence induced by quadratic system-bath interactions with analytic time-dependence. We show how to suppress such interactions to $N$-th order using only $N$ pulses. Furthermore, we show to homogenize a $2^m$-mode bosonic system using only $(N+1)^{2m+1}$ pulses, yielding - up to $N$-th order - an effective evolution described by non-interacting harmonic oscillators with identical frequencies. The decoupled and homogenized system provides natural decoherence-free subspaces for encoding quantum information. Our schemes only require pulses which are tensor products of single-mode passive Gaussian unitaries and SWAP gates between pairs of modes.