Abstract:
Quantum measurement is analyzed from a conceptual point of view by comparing weak
and strong interaction regimes using von-Neumann’s measurement model and explicit
conditions for weakness have been derived for both weak value and expectation value.
The effect of a weak interaction up to strength of orders 1 and 2 without post-selection
on the system and pointer states is studied. This engenders a simple interpretation
of the imaginary part of the weak value. A general mathematical formalism of weak
measurement within which previous results fit is derived. Effect of multiple degrees of
freedom and correlations among these within the pointer states in the context of weak
measurement is reviewed. Weak measurement is studied as a tool to create entanglement
between previously uncorrelated quantum states. A mathematical formalism irrespective
of the pointer state used is derived under which one can obtain the joint weak value of
incompatible observables as well as second order of the weak values. Using a bipartite
correlated resource state, a protocol for determination of weak value corresponding to a
weak interaction done by one party by another spatially separated party is conceptualized
and mathematically demonstrated.
