Refocusing of a qubit system coupled to an oscillator

TL;DR

This paper analyzes the effectiveness of soft refocusing pulses and sequences in preserving qubit coherence when coupled to a quantum oscillator, advancing quantum control techniques.

Contribution

It provides a detailed analysis of soft refocusing pulses and sequences for protecting qubit coherence in coupled qubit-oscillator systems.

Findings

Soft pulses can effectively refocus qubit dynamics.

Refocusing sequences improve coherence preservation.

The method extends quantum control capabilities.

Abstract

Refocusing, or dynamical decoupling, is a coherent control technique where the internal dynamics of a quantum system is effectively averaged out by an application of specially designed driving fields. The method has originated in nuclear magnetic resonance, but it was independently discovered in atomic physics as a ``coherent destruction of tunneling''. Present work deals with the analysis of the performance of ``soft'' refocusing pulses and pulse sequences in protecting the coherence of a qubit system coupled to a quantum oscillator.