Lifetime of Even-Parity States of A Bloch

Guangjiong Dong, He Yang, Fusheng Liu

Katharina Laubscher, Jay D. Sau, S. Das Sarma

A recent experiment [arXiv:2507.08795] has reported measurements of the interwire $X$-parity lifetime in a Majorana tetron device via the quantum capacitance of an auxiliary readout dot. Motivated by these measurements, we theoretically study the interwire parity lifetime in a minimal model of the coupled dot-tetron system subject to electrostatic noise. We show that coupling to the measurement dot can itself strongly modify the parity dynamics by generating an energy splitting that shifts noise-induced transitions to finite frequency and thereby stabilizes the measured states against low-frequency fluctuations. For representative noise strengths motivated by disordered nanowire devices, we find $X$-parity switching lifetimes of order microseconds in the measurement configuration even when the corresponding bare-tetron coherence time is only tens of nanoseconds long. We analyze both the dispersive regime, where the dot can be integrated out and the dynamics reduces to an effective two-level system, and the near-resonant regime, where all four low-energy states participate. In the latter case, rapid transitions organize the spectrum into two long-lived manifolds that approximately correspond to sectors of the combined dot-tetron $X$-loop parity, yielding effective two-state switching despite the underlying multilevel structure. Our results show that measurement-induced stabilization can substantially enhance the observed $X$-parity switching lifetime, such that the lifetime measured under continuous readout can greatly exceed the intrinsic idle $T_2^*$ coherence time of the isolated Majorana tetron qubit.

Markus Glück, Andrey R. Kolovsky, H. J. Korsch

The lifetime of a Bloch particle in a homogeneous field is calculated numerically as a function of the field amplitude. A simple model explaining the characteristic features of the field dependence of the lifetime is introduced. The theoretical results are compared with the experimental data of C. F. Bharucha et al. [Phys. Rev. A 55, R857 (1997)] obtained for cold sodium atoms in an accelerated optical lattice.

Masudul Haque

M. Hongoh

C. J. Bowers, Dmitry Budker, Eugene D. Commins +5 more

Lifetimes of 21 excited states in atomic Yb were measured using time-resolved fluorescence detection following pulsed laser excitation. The lifetime of the 4${\mathit{f}}^{14}$5d6${\mathit{s}}^{\mathrm{}3}$${\mathit{D}}_{1}$ state, which is of particular importance for a proposed study of parity nonconservation in atoms, was measured to be 380(30) ns. \textcopyright{} 1996 The American Physical Society.