Department of Physics

Indian Institute Of Technology Madras , Chennai

Understanding the Born Rule in Weak Measurements

Speaker : Prof. Apoorva Patel, Indian Institute of Science

2017-08-28

Abstract :

Abstract: Projective measurement is used as a fundamental axiom in quantum mechanics, even though it is discontinuous and cannot predict which measured operator eigenstate will be observed in which experimental run. The probabilistic Born rule gives it an ensemble interpretation, predicting proportions of various outcomes over many experimental runs. Understanding gradual weak measurements requires replacing this scenario with a dynamical evolution equation for the collapse of the quantum state in individual experimental runs. We revisit the framework to model quantum measurement as a continuous nonlinear stochastic process. It combines attraction towards the measured operator eigenstates with white noise, and for a specific ratio of the two reproduces the Born rule. This fluctuation-dissipation relation implies that the quantum state collapse involves the system-apparatus interaction only, and the Born rule is a consequence of the noise contributed by the apparatus. The ensemble of the quantum trajectories is predicted by the stochastic process in terms of a single evolution parameter, and matches well with the weak measurement results for superconducting transmon qubits.

Reference: A Patel, P Kumar Physical Review A 96 (2), 022108 (2017).

Key Speaker Prof. Apoorva Patel, Indian Institute of Science
Guests None
Place Seminar Room
Start Time 4:00 PM
Finish Time 5:00 PM
External Link None