Activated and non activated dephasing demonstrated in NV center dynamics

TL;DR

This paper investigates two types of dephasing mechanisms in NV centers, revealing that spin-swap dephasing can occur without initial bath activation and is temperature independent, contrasting with standard dephasing.

Contribution

It introduces and analyzes spin-swap dephasing as a new mechanism that does not require initial bath activation and is temperature independent in NV centers.

Findings

Standard dephasing is temperature dependent.

Spin-swap dephasing does not need initial bath activation.

Pure dephasing cannot be achieved with dipolar interactions due to dissipation.

Abstract

We analyze different decoherence processes in a system coupled to a bath. Apart from the well known standard dephasing mechanism which is temperature dependent an alternative mechanism is presented, the spin-swap dephasing which does not need initial bath activation and is temperature independent. We show that for dipolar interaction the separation of time scales between system and bath can not produce pure dephasing, the process being accompained by dissipation. Activated and non activated dephasing processes are demonstrated in a diamond nitrogen-vacancy (NV) center.