2005/07/26 by R. Merlin, R. Merlín, Merlin, R.
Engineering · Physics and Astronomy · #Advanced Measurement and Metrology Techniques #FOS: Physical sciences #Quantum Physics (quant-ph) #quant-ph
paper · pdf · doi:10.48550/arxiv.quant-ph/0507250
arxiv created 2005/07/26 · openalex publication_date 2005/07/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A quantum many-body model is presented with features similar to those of certain particle detectors. The energy spectrum contains a single metastable 'ready'-state and macroscopically-distinct 'pointer' states. Measurements do not pose paradoxes or require interventions outside the field theory formalism. Transitions into classical-like states can be triggered by a single particle with help of the thermal bath. Schroedinger cat states are associated with superpositions of inequivalent vacua, thus relating wavefunction collapse to the dynamics of symmetry breaking in phase transformations.