Conditional Density Matrix: Systems and Subsystems in Quantum Mechanics
Quantum Physics
2007-05-23 v1
Abstract
A new quantum mechanical notion -- Conditional Density Matrix -- is discussed and is applied to describe some physical processes. This notion is a natural generalization of von Neumann density matrix for such processes as divisions of quantum systems into subsystems and reunifications of subsystems into new joint systems. Conditional Density Matrix assigns a quantum state to a subsystem of a composite system under condition that another part of the composite system is in some pure state.
Cite
@article{arxiv.quant-ph/0210149,
title = {Conditional Density Matrix: Systems and Subsystems in Quantum Mechanics},
author = {V. V. Belokurov and O. A. Khrustalev and V. A. Sadovnichy and O. D. Timofeevskaya},
journal= {arXiv preprint arXiv:quant-ph/0210149},
year = {2007}
}
Comments
14 pages, LaTEX