Coherent manipulation of electron spins up to ambient temperatures in Cr$^{5+}$(S=1/2) doped K$_3$NbO$_8$

TL;DR

This study demonstrates room-temperature coherent control of Cr$^{5+}$ electron spins in K$_3$NbO$_8$, showing potential for solid-state quantum computing with long coherence times and observable Rabi oscillations.

Contribution

It reports the first observation of Rabi oscillations in a transition metal oxide spin system at ambient temperature, highlighting its potential for quantum information applications.

Findings

Rabi oscillations observed up to room temperature

Phase coherence time $T_2$ reaches ~10 microseconds at low temperature

Single qubit figure of merit $Q_M$ of about 500

Abstract

We report coherent spin manipulation on Cr$^{5+}$ (\emph{S} = 1/2, \emph{I} = 0) doped K$_3$NbO$_8$, which constitutes a dilute two-level model relevant for use as a spin qubit. Rabi oscillations are observed for the first time in a spin system based on transition metal oxides up to room temperature. At liquid helium temperature the phase coherence relaxation time \emph{$T_2$} reaches $\sim 10$ $\mu$s and, with a Rabi frequency of 20 MHz, yields a single qubit figure of merit \emph{$Q_M$} of about 500. This shows that a diluted ensemble of Cr$^{5+}$ (\emph{S} = 1/2) doped K$_3$NbO$_8$ is a potential candidate for solid-state quantum information processing.