Shortcuts to adiabaticity with a quantum control field

TL;DR

This paper demonstrates how coupling a Landau-Zener qubit to a second quantum system can significantly suppress non-adiabatic transitions, providing a quantum control method for faster adiabatic processes.

Contribution

It introduces a quantum control scheme using autonomous quantum dynamics to implement shortcuts to adiabaticity by coupling systems, reducing non-adiabatic errors.

Findings

Coupling strength tuning reduces unwanted transitions by over two orders of magnitude.

Quantum properties of control fields are essential for effective shortcuts.

The method applies to quantum state transfer in the Landau-Zener model.

Abstract

Quantum adiabatic dynamics is the crucial element of adiabatic quantum computing and quantum annealing. Shortcuts to adiabaticity enable acceleration of the computational time by suppressing unwanted non-adiabatic processes with designed classical fields. Here, we consider quantum state transfer in the Landau-Zener model, which exemplifies the key elements of quantum adiabatic dynamics. We argue that non-adiabatic transitions can be suppressed by autonomous quantum dynamics, which involves coupling the Landau-Zener qubit to a second quantum system. By tuning the coupling strength, the composite quantum dynamics can reduce the probability of unwanted processes by more than two orders of magnitude. This is a prime example of control where the quantum properties of the control fields are key for implementing shortcuts to adiabaticity.