Quantum Zeno and anti-Zeno effect of a nanomechanical resonator measured by a point contact

The occurrence of either the quantum Zeno effect (QZE) or anti-Zeno effect (AZE) resulting from the short-time behavior of the environment-induced decoherence for quantum Brownian motion (QBM) model has been discussed [S. Maniscalco, J. Piilo, and K. A. Suominen, Phys. Rev. Lett. 97, 130402 (2006)]. We discuss here while the shuttering time period (length) of the frequent observations is changed, the system of interest, i.e., a nanomechanical oscillator, will undergo a QZE to AZE crossover. Instead of interacting with an equilibrium bosonic bath in a QBM model, we investigate the occurrence of either QZE or AZE of a nanomechanical oscillator coupled to a nonequilibrium fermionic reservoir [quantum point contact (QPC) detector as a measuring device]. We find that Zeno and anti-Zeno behaviors depend on the values of the system and reservoir parameters such as the oscillator frequency, energy cutoff, bias voltage, and reservoir temperature.