Qubits as devices to detect the third moment of current fluctuations

Abstract

Under appropriate conditions controllable two-level systems can be used to detect the third moment of current fluctuations. We derive a Master Equation for a quantum system coupled to a bath valid to the third order in the coupling between the system and the environment. In this approximation the reduced dynamics of the quantum system depends on the frequency dependent third moment. Specializing to the case of a controllable two-level system (a qubit) and in the limit in which the splitting between the levels is much smaller than the characteristic frequency of the third moment, it is possible to show that the decay of the qubit has additional oscillations whose amplitude is directly proportional to the value of the third moment. We discuss an experimental setup where this effect can be seen.

10 pages, 7 figures

References in corpus (1)

• Temperature dependent third cumulant of tunneling noise

Cited by in corpus (6)

• Frequency-dependent current correlation functions from scattering theory
• Josephson junction detector of non-Gaussian noise
• Detection of finite frequency current moments with a dissipative resonant circuit
• Quantum detectors for the third cumulant of current fluctuations
• Superconductor-metal transition in an ultrasmall Josephson junction biased by a noisy voltage source
• Measuring the distribution of current fluctuations through a Josephson junction with very short current pulses