Non-adiabatic Fast Control of Mixed States based on Lewis-Riesenfeld Invariant

TL;DR

This paper introduces a fast, inverse-engineered control method for mixed quantum states using Lewis-Riesenfeld invariants, significantly improving speed and efficiency over traditional adiabatic methods for quantum computation.

Contribution

It develops a novel inverse-engineering approach for rapid control of mixed states, including a new antedated control technique, optimizing speed and energy cost.

Findings

Control passages are significantly faster than adiabatic methods.

Antedated control further accelerates quantum state manipulation.

Control parameters can be tuned for optimal speed and energy efficiency.

Abstract

We apply the inversely-engineered control method based on Lewis-Riesenfeld invariants to control mixed states of a two-level quantum system. We show that the inversely-engineered control passages of mixed states - and pure states as special cases - can be made significantly faster than the conventional adiabatic control passages, which renders the method applicable to quantum computation. We devise a new type of inversely-engineered control passages, to be coined the antedated control passages, which further speed up the control significantly. We also demonstrate that by carefully tuning the control parameters, the inversely-engineered control passages can be optimized in terms of speed and energy cost.