Environmental Noise on a Qubit Through Entanglement with a Quantum Circuit
Lin Tian, Seth Lloyd, Terry P. Orlando · Optical Fiber Communication Conference and International Conference on Quantum Information · 2001
An external quantum system that interacts with a qubit transmits its environmental noise to the qubit and induces qubit decoherence and relaxation. We present a general method to derive the noise spectrum of this composite environment for arbitrary quantum circuits. The method is applied to the measurement induced noise of the superconducting persistent current qubit.