Investigations on quantum-memory-assisted entropic uncertainty relation between coupled qubits in squeezed vacuum reservoir

Abstract

We investigate the quantum-memory-assisted entropic uncertainty relation between coupled qubits which are initially in entangled mixed states in squeezed vacuum reservoir. We find that the uncertainty of quantum system is dependent on the squeezing effect of optical field. In the squeezed vacuum reservoir, the smaller the squeezed amplitude parameter is, the smaller the entropic uncertainties and its lower bound are, the more favorable to improve the accuracy of quantum measurement. Through optimizing the parameters of the initial quantum state, the measurement precision of observable mechanical quantity can be improved. In particular, when the relative phase of the initial quantum state is an integer multiple of ⁡π, the lower bound of the entropic uncertainty reaches a minimum.