Quantifying quantum reference frames in composed systems: Local, global, and mutual asymmetries

Author(s)

Martinelli, Tiago ; Soares-Pinto, Diogo O.

• Document type: Journal article
• Source: PHYSICAL REVIEW A; v. 99, n. 4, p. 10-pg., 2019-04-26.

Abstract

The Page-Wootters mechanism questioned the fundamental nature of time in quantum physics. The mechanism explored the notion that a given physical quantity is always defined and measured relative to a reference frame, in general, not explained in the theoretical description of quantum physical experiments. Recently, the resource theory of asymmetry deals explicitly with the physical conditions necessary for a quantum system to serve as a good reference frame. Nonetheless, to quantify a quantum reference frame in relation to another one, it is important to establish an internal description of quantum theory, i.e., without the need for a classical reference frame. In this work, we address this issue with the concept of mutual asymmetry and use this machinery in the Page-Wootters mechanism by identifying the concept of mutual asymmetry as mutual or internal coherence. To do so, the notion of quantum coherence in relation to a quantum reference frame is revisited and a quantifier is proposed in this scenario. Also, this opens space to investigate the link of internal coherence and correlations, as proposed by Page and Wootters, under a resource theory approach. (AU)

• FAPESP's process: 17/07973-5 - Thermodynamics and information technologies with continuous variable quantum systems
• Grantee: Gabriel Teixeira Landi
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/03727-0 - Quantumness of composite systems: geometry, dynamics and thermodynamics
• Grantee: Diogo de Oliveira Soares Pinto
• Support Opportunities: Regular Research Grants