Quantum information transfer using weak measurements and any non-product resource state

Abstract

Information about an unknown quantum state can be encoded in weak values of projectors belonging to a complete eigenbasis. A protocol that enables one party—Bob—to remotely determine the weak values corresponding to weak measurements performed by another spatially separated party—Alice is presented. The particular set of weak values contains complete information of the quantum state encoded on Alice’s register, which enacts the role of preselected system state in the aforementioned weak measurement. Consequently, Bob can determine the quantum state from these weak values, which can also be termed as remote state determination or remote state tomography. A combination of non-product bipartite resource state shared between the two parties and classical communication between them is necessary to bring this statistical scheme to fruition. Significantly, the information transfer of a pure quantum state of any known dimensions can be effected even with resource states of low dimensionality and purity with a single measurement setting at Bob’s end.