2003/09/30 by Lars M. Johansen · 55 citations
Computer Science · Mathematics · Physics and Astronomy · #Coherent states #Mathematics #Observable #Optics #Physics #Quadrature (astronomy) #Quantum #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum mechanics #Statistical Mechanics and Entropy #Statistical physics #quant-ph
paper · pdf · doi:10.1016/j.physleta.2004.07.003
published in Physics Letters A 329(3), 184-187 (Elsevier BV) · 4 pages. Some arguments rewritten, reference added to quant-ph/0402050. Conclusion unchanged
arxiv created 2004/02/07 · openalex publication_date 2004/07/22 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
It is demonstrated that a weak measurement of the squared quadrature observable may yield negative values for coherent states. This result cannot be reproduced by a classical theory where quadratures are stochastic c-numbers. The real part of the weak value is a conditional moment of the Margenau-Hill distribution. The nonclassicality of coherent states can be associated with negative values of the Margenau-Hill distribution. A more general type of weak measurement is considered, where the pointer can be in an arbitrary state, pure or mixed.