Single-shot measurement of triplet-singlet relaxation in a Si/SiGe double quantum dot

TL;DR

This paper measures the lifetimes of two-electron spin states in a Si/SiGe double quantum dot, revealing how magnetic fields influence triplet state relaxation times, with implications for quantum computing.

Contribution

It introduces a single-shot measurement technique to simultaneously determine multiple spin state lifetimes in a Si/SiGe double quantum dot.

Findings

Triplet states have ~10 ms lifetime at zero magnetic field.

T- state lifetime increases to 3 seconds at 1 Tesla.

T0 state lifetime remains unchanged with magnetic field.

Abstract

We investigate the lifetime of two-electron spin states in a few-electron Si/SiGe double dot. At the transition between the (1,1) and (0,2) charge occupations, Pauli spin blockade provides a readout mechanism for the spin state. We use the statistics of repeated single-shot measurements to extract the lifetimes of multiple states simultaneously. At zero magnetic field, we find that all three triplet states have equal lifetimes, as expected, and this time is ~10 ms. At non-zero field, the T0 lifetime is unchanged, whereas the T- lifetime increases monotonically with field, reaching 3 seconds at 1 T.