Is Wave Function Collapse Necessary? Explaining Quantum Nondemolition Measurement of a Spin Qubit within Linear Evolution
Year: 2024
Type: article
Abstract: The measurement problem dates back to the dawn of quantum mechanics. Here, we measure a quantum dot electron spin qubit through off-resonant coupling with a highly redundant ancilla, consisting of thousands of nuclear spins. Large redundancy allows for single-shot measurement with high fidelity ≈99.85%. Repeated measurements enable heralded initialization of the qubit and backaction-free detection of electron spin quantum jumps, attributed to burstlike fluctuations in a thermally populated phonon bath. Based on these results we argue that the measurement, linking quantum states to classical observables, can be made without any "wave function collapse" in agreement with the Quantum Darwinism concept.
Source: Physical Review Letters
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,750
Awards: G1033374213, Multiphoton Experiments with Semiconductor Quantum Dots, Advanced Entanglement from Quantum Dots, Hyper-entanglement from ultra-bright photon pair sources (HYPER-U-P-S), On-chip quantum photonics for complex quantum networking, G3112983486, Single-atom quantum phenomena in nanoscale semiconductor devices, Single-atom quantum phenomena in nanoscale semiconductor devices, G5228700557
OpenAlex ID: W4394943514