Decoherence and Wavefunction Collapse in Quantum Measurements

Lokesh kumar reddy Thummala

Михаил Борисович Менский

Garrelt Quandt-Wiese

A novel approach for measuring wavefunction collapse is proposed which, unlike interferometric measurements, is not affected by decoherence. A mirror of a Michelson interferometer is transferred into a quantum superposition, where the decay of the mirror superposition is measured by the fact that it affects the probability of detecting photons in the interferometer. The experiment can be realised with currently available technology for photon generation and detection and is suitable for testing collapse models, which is shown by calculating the expected outcomes for the gravity-based models of Diósi and Penrose.

C. P. Sun, X. X. Yi, Shou-Xin Zhao +2 more

A novel dynamic model for wavefunction collapse in cavity quantum electrodynamics (QED) is proposed associated with the gedanken Stern - Gerlach experiment of the quantized magnetic field. It is used to describe and test the fundamental problems of quantum measurements, such as wavefunction collapse, Schrödinger entanglement states (cats) and quantum decoherence. This model also manifests rich phenomena in atomic optics, such as the splitting of atomic beams, and the generation of even- and odd-coherent states. It is also shown that this model possesses a factorizable structure which has been found in the other dynamic models for wavefunction collapse.

Michael B. Mensky

Everett X. Wang

Despite its remarkable success in describing microscopic phenomena, quantum mechanics continues to pose unresolved foundational questions concerning measurement, nonlocality, wavefunction collapse, and the nature of physical reality. These issues were highlighted by the EPR paradox1-2, in which Einstein and his co-authors examined the measurement of entangled particles in space-like separation. Quantum mechanics predicts that measuring one particle’s observable instantaneously determines the state of the other, seemingly violating special relativity’s prohibition of faster-than-light influences and suggesting an incomplete description of physical reality. However, Bell’s theorem3-5, along with the Bell-Kochen-Specker theorem6-10 and subsequent experiments, has largely ruled out local hidden variable theories. In this work, I apply the quantum decoherence framework11-13, pioneered by Zeh, Zurek, Joos and Leggett et al. to analyze an EPR-like system using system-environment interactions as a measurement model. I demonstrate that measurement on one entangled particle does not instantaneously collapse the system's wavefunction. Instead, the local wavefunctions of the measured particle and its environment evolve dynamically, while the remote particle’s wavefunction remains unchanged. Environment-induced decoherence selects pointer states and rapidly suppresses quantum correlations through local interactions, giving rise to the appearance of wavefunction collapse. These findings suggest that quantum mechanics can be reconciled with local realism if the wavefunction is treated as an ontic entity, offering a potential path toward a locally realistic quantum theory in alignment with Einstein’s vision.