Experimental Proof of Nonlocal Wavefunction Collapse for a Single Particle Using Homodyne Measurement
arXiv:1412.7790 · doi:10.1038/ncomms7665
Abstract
A single quantum particle can be described by a wavefunction that spreads over arbitrarily large distances, but it is never detected in two (or more) places. This strange phenomenon is explained in quantum theory by what Einstein repudiated as "spooky action at a distance": the instantaneous nonlocal collapse of the wavefunction to wherever the particle is detected. We demonstrate this single-particle spooky action, for the first time with no efficiency loophole, by splitting a single photon between two laboratories and experimentally testing if the choice of measurement in one lab really causes a change in the local quantum state in the other lab. To this end, we use homodyne measurements with six different measurement settings and quantitatively verify Einstein's spooky action by violating an Einstein-Podolsky-Rosen-steering inequality by . Our experiment also verifies the entanglement of the split single photon even when one side is untrusted.
8 pages, 5 figures
References in corpus (9)
- Steering, Entanglement, Nonlocality, and the EPR Paradox
- Experimental criteria for steering and the Einstein-Podolsky-Rosen paradox
- Observation of one-way Einstein-Podolsky-Rosen steering
- Nonlocality of a single particle
- Witnessing trustworthy single-photon entanglement with local homodyne measurements
- Purification of Single-photon Entanglement
- Nonlocality of a single photon: paths to an EPR-steering experiment
- Generation and Eight-port Homodyne Characterization of Time-bin Qubits for Continuous-variable Quantum Information Processing
- Entanglement and Symmetry: A Case Study in Superselection Rules, Reference Frames, and Beyond