Parity measurement is a key step in many entanglement generation and quantum error correction schemes. We propose a protocol for non-destructive parity measurement of two remote qubits, i.e., macroscopically separated qubits with no direct interactio
n. The qubits are instead dispersively coupled to separate resonators that radiate to shared photodetectors. The scheme is deterministic in the sense that there is no fundamental bound on the success probability. Compared to previous proposals, our protocol addresses the scenario where number resolving photodetectors are available but the qubit-resonator coupling is time-independent and only dispersive.
A hybrid system that combines the advantages of a superconducting flux qubit and an electron spin ensemble in diamond is one of the promising devices to realize quantum information processing. Exploring the properties of the superconductor diamond sy
stem is essential for the efficient use of this device. When we perform spectroscopy of this system, significant power broadening is observed. However, previous models to describe this system are known to be applicable only when the power broadening is negligible. Here, we construct a new approach to analyze this system with strong driving, and succeed to reproduce the spectrum with the power broadening. Our results provide an efficient way to analyze this hybrid system.
