In this letter, we present a new procedure to determine completely the complex modular values of arbitrary observables of pre- and post-selected ensembles, which works experimentally for both weak and strong measurement strengths. By controlling simultaneously the visibility and the phase of an interferometric experiment involving a qubit meter, we determine directly both the modulus and the argument of the modular value as a function of the measurement strength. Modular and weak values are closely related. When two entangled qubits are used as the probed and meter systems, the phase of the modular and weak values has a topological origin. Its physical significance can thus be used to evaluate the quantumness of weak values.
|Article number||arXiv:1508.01353 [quant-ph]|
|Number of pages||6|
|Publication status||Submitted - 2015|