Full counting statistics of quantum phase slips

We work out a microscopic theory describing complete statistics of voltage fluctuations generated by quantum phase slips (QPS) in superconducting nanowires. We evaluate the cumulant generating function and demonstrate that shot noise of the voltage as well as the thir d and all higher voltage cumulants differ from zero only due to the presence of QPS. In the zero-frequency limit voltage fluctuations in superconducting nanowires are described by Poisson statistics just as in a number of other tunnelinglike problems. However, at nonzero frequencies quantum voltage fluctuations in superconducting nanowires become much more complicated and are not anymore accounted for by Poisson statistics. In the case of short superconducting nanowires we explicitly evaluate all finite-frequency voltage cumulants and establish a nontrivial relation between these cumulants and the current-voltage characteristics of our system.

Figure 1

The system under consideration.

Figure 2

Real and imaginary parts of the third voltage cumulant at $T\to 0$ and $\mu =1.1$.

Figure 3

The same as in Fig. 2 at $T=I{\mathrm{\Phi }}_0$.