Unified generation and fast emission of arbitrary single-photon multimode W states
Jun‐Cong Zheng, Jie Peng, Pinghua Tang, Fei Li, Na Tan · Physical Review A · 2022
We propose a unified and deterministic scheme to generate arbitrary single-photon multimode $W$ states in circuit QED. A three-level system (qutrit) is driven by a pump-laser pulse and coupled to $N$ spatially separated resonators. The coupling strength for each spatial mode ${g}_{i}$ totally decide the generated single-photon $N$-mode $W$ state $|{W}_{N}\ensuremath{\rangle}=\frac{1}{A}{\ensuremath{\sum}}_{i=1}^{N}{g}_{i}|{0}_{1}{0}_{2}\ensuremath{\cdots}{1}_{i}{0}_{i+1}\ensuremath{\cdots}{0}_{N}\ensuremath{\rangle}$, so arbitrary $|{W}_{N}\ensuremath{\rangle}$ can be generated inside resonators by adjusting ${g}_{i}$ and $N$. Moreover, such $W$ states can be fast emitted in symmetric temporal waveform with a probability reaching $98.9%$. The generation (or emission) time and fidelity can both be the same for arbitrary $|{W}_{N}\ensuremath{\rangle}$, independent of mode numbers. Finally, the time evolution process is easy to control since only the pump pulse is time-dependent.