Extending the Electron Spin Coherence Time of Atomic Hydrogen by Dynamical Decoupling

TL;DR

This study demonstrates that applying dynamical decoupling sequences extends the electron spin coherence time of atomic hydrogen in a molecular cage, revealing multiple noise sources affecting quantum coherence.

Contribution

It introduces the use of CPMG sequences to significantly enhance electron spin coherence time and identifies high-frequency noise sources in atomic hydrogen systems.

Findings

Maximum T2 of 56 microseconds achieved

Suppression of low-frequency nuclear spin noise

Identification of high-frequency noise sources

Abstract

We study the electron spin decoherence of encapsulated atomic hydrogen in octasilsesquioxane cages induced by the 1H and 29Si nuclear spin bath. By applying the Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence we significantly suppress the low-frequency noise due to nuclear spin flip-flops up to the point where a maximum T2 = 56 us is observed. Moreover, dynamical decoupling with the CPMG sequence reveals the existence of two sources of high-frequency noise: first, a fluctuating magnetic field with the proton Larmor frequency, equivalent to classical magnetic field noise imposed by the 1H nuclear spins of the cage organic substituents, and second, decoherence due to entanglement between the electron and the inner 29Si nuclear spin of the cage.