Figure 1

Coherence dependence on quantum-statistics for qubit coupled to a Lorentzian bath. (a) The free evolution of the qubit coherence ${\rho }_S^{+-}(t)$ is shown to be faster when the bath consists of spins (solid blue line) than when it consists of oscillators (dashed green line). Time is in coupling strength units ${\eta }^{-1}$. The inset shows the evolution for longer times. (b) The relative change (enhancement) of qubit coherence in the presence of control with respect to its free evolution for spin and oscillator baths, under periodic $\pi$ pulses applied at a rate $\tau =T/n$, where $T$ is the total time and $n$ is the total number of pulses.Reuse & Permissions

Figure 2

Quantum Zeno (QZE) to anti-Zeno (AZE) crossover for qubit coupled to a Lorentzian bath under periodic $\pi$ pulses. The relative change (enhancement) of qubit coherence in the presence of control with respect to its free evolution for (a) spin and (b) oscillator baths is plotted as a function of the pulse interval $\tau$ (in units of inverse bath correlation time, $\Gamma$) and pulse number $n$. The transition from QZE (coherence enhancement) to AZE (coherence suppression) for bosonic baths is exactly at the bath correlation time $1/\Gamma$, while for spin baths it is well within the bath correlation time.Reuse & Permissions