Weak antilocalization and UCFs in an open bismuth quantum dot

We report on the observation of weak antilocalization and universal conductance fluctuations in the magnetoconductance of an open quasi-ballistic bismuth nano-cavity. The electron decoherence length is comparable to sample dimensions at low temperature, while the spin–orbit coupling length is smaller. The temperature dependence of both the conductance and the dephasing length are consistent with two-dimensional electron–electron interactions being the dominant decoherence process.