Back-action effects in charge detection

Charge detection offers a powerful probe of mesoscopic structures based on quantum dots, but it also invariably results in measurement back-action (MBA). If strong, MBA can be detrimental to the physical properties being probed. In this work, we focus on the effects of MBA on an Anderson impurity model in which the impurity is coupled electrostatically to a detector. Introducing a nonperturbative method, we explore the interplay of coherent dynamics, strong correlations, and nonequilibrium conditions. The effects of MBA can be seen most clearly in the temperature derivative of the occupation. In the nonequilibrium case, we identify this as arising because of an energy flow from the detector to the impurity.