Measurement problem in quantum mechanics: characteristics of an apparatus

Deepak Kumar, (1998) Measurement problem in quantum mechanics: characteristics of an apparatus Pramana - Journal of Physics, 51 (5). pp. 567-575. ISSN 0304-4289

PDF - Publisher Version

Official URL:

Related URL:


The problem of measurement in Quantum Mechanics will be briefly reviewed. Since the measurement process involves a macroscopic apparatus, the attention is focussed on the dynamics of a pointer-like variable of the apparatus when it interacts with a quantum system. It is argued that since the measurement process requires an apparent collapse of the wave function in a certain basis, and collapse is an irreversible process, understanding of irreversibility in a quantum macroscopic system is crucial. The chief characteristics of an apparatus that are important in understanding measurement process are (a) its closely spaced energy levels and (b) its interaction with environment. The coupling with the environment drives the density matrix of the apparatus to diagonal form, but to have persistent correlations between system and apparatus states, it seems necessary to have a pointer variable that has a classical limit.

Item Type:Article
Source:Copyright of this article belongs to Indian Academy of Sciences.
Keywords:Measurement; Wavefunction Collapse; Irreversibility; Density Matrix; Macroscopic Apparatus
ID Code:9923
Deposited On:02 Nov 2010 10:26
Last Modified:16 May 2016 19:38

Repository Staff Only: item control page