Observing a Quantum Measurement
arXiv:2105.00061 · doi:10.1007/s10701-021-00522-0
Abstract
With the example of a Stern-Gerlach measurement on a spin-1/2 atom, we show that a superposition of both paths may be observed compatibly with properties attributed to state collapse - for example, the singleness (or mutual exclusivity) of outcomes. This is done by inserting a quantum two-state system (an ancilla) in each path, capable of responding to the passage of the atom, and thus acting as a virtual detector. We then consider real measurements on the compound system of atomic spin and two ancillae. Nondestructive measurements of a set of compatible joint observables can be performed, one for a superposition and others for collapse properties. A novel perspective is given as to why, within unitary quantum theory, ordinary measurements are blind to such superpositions. Implications for the theory of measurement are discussed.
arXiv comment21 pages, 3 figures
References in corpus (20)
- Decoherence, einselection, and the quantum origins of the classical
- Quantum secret sharing
- Models of Wave-function Collapse, Underlying Theories, and Experimental Tests
- 14-qubit entanglement: creation and coherence
- Observation of three-photon Greenberger-Horne-Zeilinger entanglement
- Dynamical Reduction Models
- Generation and manipulation of Schrödinger cat states in Rydberg atom arrays
- Preparation and Measurement of Three-Qubit Entanglement in a Superconducting Circuit
- Experimental realization of Wheeler's delayed-choice GedankenExperiment
- Quantum Darwinism
- Quantum Decoherence
- Observation of multi-component atomic Schrödinger cat states of up to 20 qubits
- A Snapshot of Foundational Attitudes Toward Quantum Mechanics
- Quantum Information Theory of Entanglement and Measurement
- Irreversibility and the arrow of time in a quenched quantum system
- A proposal for the experimental detection of CSL induced random walk
- The measurement postulates of quantum mechanics are operationally redundant
- Tracking the dynamics of an ideal quantum measurement
- Delayed-choice quantum eraser for the undergraduate laboratory
- Understanding the Pointer States