TY - JOUR

T1 - What Is Nonlocal in Counterfactual Quantum Communication?

AU - Aharonov, Yakir

AU - Rohrlich, Daniel

N1 - Publisher Copyright:
© 2020 American Physical Society.

PY - 2020/12/21

Y1 - 2020/12/21

N2 - We revisit the "counterfactual quantum communication"of Salih et al. [1], who claim that an observer "Bob"can send one bit of information to a second observer "Alice"without any physical particle traveling between them. We show that a locally conserved, massless current - specifically, a current of modular angular momentum, Lz mod 2ℏ - carries the one bit of information. We integrate the flux of Lz mod 2ℏ from Bob to Alice and show that it equals one of the two eigenvalues of Lz mod 2ℏ, either 0 or ℏ, thus precisely accounting for the one bit of information he sends her. We previously [2] obtained this result using weak values of Lz mod ℏ; here we do not use weak values.

AB - We revisit the "counterfactual quantum communication"of Salih et al. [1], who claim that an observer "Bob"can send one bit of information to a second observer "Alice"without any physical particle traveling between them. We show that a locally conserved, massless current - specifically, a current of modular angular momentum, Lz mod 2ℏ - carries the one bit of information. We integrate the flux of Lz mod 2ℏ from Bob to Alice and show that it equals one of the two eigenvalues of Lz mod 2ℏ, either 0 or ℏ, thus precisely accounting for the one bit of information he sends her. We previously [2] obtained this result using weak values of Lz mod ℏ; here we do not use weak values.

UR - http://www.scopus.com/inward/record.url?scp=85099126024&partnerID=8YFLogxK

U2 - 10.1103/PhysRevLett.125.260401

DO - 10.1103/PhysRevLett.125.260401

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C2 - 33449741

AN - SCOPUS:85099126024

SN - 0031-9007

VL - 125

JO - Physical Review Letters

JF - Physical Review Letters

IS - 26

M1 - 260401

ER -