Exact decoherence and orthogonality of pointer states in the measurement of a qubit observable without an environment

Authors

  • John Paul Adubo Besagas ⋅ PH National Institute of Physics, University of the Philippines Diliman
  • Jan Carlo Lubao Lima ⋅ PH National Institute of Physics, University of the Philippines Diliman
  • Eric Alvarez Galapon ⋅ PH National Institute of Physics, University of the Philippines Diliman

Abstract

We apply the work of E. A. Galapon [EPL 113 60007, (2016)] in the measurement of the z-component of an electron by means of a measuring instrument which is decomposed into a probe and a pointer, with the probe being inaccessible from observation. It is found that if the probe is initially prepared in a momentum-limited state, the coherences of the system-pointer reduced density matrix vanishes identically to zero at a finite time without an environment. Moreover, it is shown that in the case of a momentum-limited initial state of the pointer, the pointer states are exactly orthogonal. In this scheme,  exact decoherence is attained at an earlier time before the pointer states become exactly orthogonal. 

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Article ID

SPP-2017-1C-01

Section

Theoretical and Mathematical Physics

Published

2017-06-07

How to Cite

[1]
JPA Besagas, JCL Lima, and EA Galapon, Exact decoherence and orthogonality of pointer states in the measurement of a qubit observable without an environment, Proceedings of the Samahang Pisika ng Pilipinas 35, SPP-2017-1C-01 (2017). URL: https://proceedings.spp-online.org/article/view/140.