Optimal Quantum State Tomography via Weak Value

Abstract

To improve the efficiency of the state tomography strategy via weak value, we have searched the optimal coupling strength between the system and measuring device. For an arbitrary d-dimensional quantum system, the optimal strengths being used in measuring the real and imaginary parts of the density matrix are obtained. The optimal efficiency of the state tomography has also been studied by using mean square error. The minimal mean square errors in the reconstructed density matrices have been derived. The state tomography strategy studied in this article may be useful in the measurement of the unknown quantum states.