Title: Quantum reversibility is relative, or does a quantum measurement reset initial conditions?

Abstract

I compare the role of the information in classical and quantum dynamics by examining the relation between information flows in measurements and the ability of observers to reverse evolutions. I show that in the Newtonian dynamics reversibility is unaffected by the observer’s retention of the information about the measurement outcome. By contrast—even though quantum dynamics is unitary, hence, reversible—reversing quantum evolution that led to a measurement becomes, in principle, impossible for an observer who keeps the record of its outcome. Thus, quantum irreversibility can result from the information gain rather than just its loss—rather than just an increase of the (von Neumann) entropy. Recording of the outcome of the measurement resets, in effect, initial conditions within the observer’s (branch of) the Universe. Nevertheless, I also show that the observer’s friend—an agent who knows what measurement was successfully carried out and can confirm that the observer knows the outcome but resists his curiosity and does not find out the result—can, in principle, undo the measurement. This relativity of quantum reversibility sheds new light on the origin of the arrow of time and elucidates the role of information in classical and quantum physics. In conclusion, quantum discord appears as a natural measuremore » of the extent to which dissemination of information about the outcome affects the ability to reverse the measurement.« less

Authors:

Zurek, Wojciech H. ^[1]

---

+ Show Author Affiliations

1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Publication Date:

2018-05-28

Research Org.:

Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

USDOE Laboratory Directed Research and Development (LDRD) Program

OSTI Identifier:

1467216

Report Number(s):

LA-UR-18-22300
Journal ID: ISSN 1364-503X

Grant/Contract Number:  

AC52-06NA25396

Resource Type:

Accepted Manuscript

Journal Name:

Philosophical Transactions of the Royal Society. A, Mathematical, Physical and Engineering Sciences

Additional Journal Information:

Journal Volume: 376; Journal Issue: 2123; Journal ID: ISSN 1364-503X

Publisher:

The Royal Society Publishing

Country of Publication:

United States

Language:

English

Subject:

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Mathematics