  
  
Stat 
Members: 3015 Articles: 2'084'010 Articles rated: 2587
18 June 2021 

   

Article overview
 

Towards Quantum Information Theory in Space and Time  Igor V. Volovich
;  Date: 
6 Mar 2002  Subject:  Quantum Physics; Mesoscopic Systems and Quantum Hall Effect  quantph condmat.meshall grqc hepth  Abstract:  Modern quantum information theory deals with an idealized situation when the spacetime dependence of quantum phenomena is neglected. However the transmission and processing of (quantum) information is a physical process in spacetime. Therefore such basic notions in quantum information theory as qubit, channel, composite systems and entangled states should be formulated in space and time. In particlular we suggest that instead of a two level system (qubit) the basic notion in a relativistic quantum information theory should be a notion of an elementary quantum system, i.e. an infinite dimensional Hilbert space $H$ invariant under an irreducible representation of the Poincare group labeled by $[m,s]$ where $mgeq 0$ is mass and $s=0,1/2,1,...$ is spin. We emphasize an importance of consideration of quantum information theory from the point of view of quantum field theory. We point out and discuss a fundamental fact that in quantum field theory there is a statistical dependence between two regions in spacetime even if they are spacelike separated. A classical probabilistic representation for a family of correlation functions in quantum field theory is obtained. Entangled states in space and time are considered. It is shown that any reasonable state in relativistic quantum field theory becomes disentangled (factorizable) at large spacelike distances if one makes local observations. As a result a violation of Bell`s inequalities can be observed without inconsistency with principles of relativistic quantum theory only if the distance between detectors is rather small. We suggest a further experimental study of entangled states in spacetime by studying the dependence of the correlation functions on the distance between detectors.  Source:  arXiv, quantph/0203030  Services:  Forum  Review  PDF  Favorites 


No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser CCBot/2.0 (https://commoncrawl.org/faq/)

 



 News, job offers and information for researchers and scientists:
 