2013/12/06 by Shakib Daryanoosh, Howard M. Wiseman, Howard M Wiseman · 2 citations
Computer Science · Physics and Astronomy · #Diffusion #Homodyne detection #Open quantum system #Quantum #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum discord #Quantum dynamics #Quantum process #Quantum system #quant-ph #stochastic dynamics and bifurcation
paper · pdf · doi:10.1088/1367-2630/16/6/063028
published as New J. Phys. 16, 063028 (2014) · 7 pages, 2 figures
arxiv created 2013/12/06 · openalex publication_date 2014/06/13 · arxiv updated 2014/06/17 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
It was recently argued (Wiseman and Gambetta 2012 Phys. Rev. Lett. 108 220402 ) that the stochastic dynamics (jumps or diffusion) of an open quantum system are not inherent to the system, but rather depend on the existence and nature of a distant detector. The proposed experimental tests involved homodyne detection, giving rise to quantum diffusion, and required efficiencies of well over 50%. Here we prove that this requirement ( ) is universal for diffusive-type detection, even if the system is coupled to multiple baths. However, this no-go theorem does not apply to quantum jumps, and we propose a test involving a qubit with jump-type detectors, with a threshold efficiency of only 37%. That is, quantum jumps are 'more quantum', and open the way to practical experimental tests. Our scheme involves a novel sort of adaptive monitoring scheme on a system coupled to two baths.