Superposition of Quantum Gaussian Processes: Application in Qubits’ Parity Measurements

The Gaussian formalism of Continuous Variables (CV) describe a vast number of systems, from quantum optics to circuit electrodynamics, allowing an operational description suitable for experiments. After an introduction to this topic, I present a generalization of the Gaussian formalism to describe CV systems interacting with qubits and qudits, resulting in quantum superpositions of Gaussian processes. The dispersive interaction between qubits and resonators can be described by this formalism, showcased via two examples: (a) measurement-based entanglement between two qubits, (b) detection of non-classicality of a qubit ensemble via parity measurement induced disturbance. The latter is applied to benchmark IBM’s quantum computers, detecting non-classicality up to 35 qubits via repetitive parity measurements. 

 

 

Main reference: https://arxiv.org/abs/2510.01156