We investigate time operators in the context of quantum time crystals in ring systems. A generalized commutation relation called the generalized weak Weyl relation is used to derive a class of self-adjoint time operators for ring systems with a periodic time evolution: The conventional Aharonov-Bohm time operator is obtained by taking the infinite-radius limit. Then, we discuss the connection between time operators, time crystals and real-space topology. We also reveal the relationship between our time operators and a $\mathcal{PT}$ -symmetric time operator. These time operators are then used to derive several energy-time uncertainty relations.We investigate time operators in the context of quantum time crystals in ring systems. A generalized commutation relation called the generalized weak Weyl relation is used to derive a class of self-adjoint time operators for ring systems with a periodic time evolution: The conventional Aharonov-Bohm time operator is obtained by taking the infinite-radius limit. Then, we discuss the connection between time operators, time crystals and real-space topology. We also reveal the relationship between our time operators and a $\mathcal{PT}$-symmetric time operator. These time operators are then used to derive several energy-time uncertainty relations.

arXiv:1711.10179Nov 28, 20170 citations

Time operator

В. В. Ласуков, A. N. Kharlova

Russian Physics JournalMar 1, 200817 citations

Time operators and time crystals: self-adjointness by topology change

Keiji Nakatsugawa, Toshiyuki Fujii, Avadh Saxena +1 more

Abstract We investigate time operators in the context of quantum time crystals in ring systems. A generalized commutation relation called the generalized weak Weyl relation is used to derive a class of self-adjoint time operators for ring systems with a periodic time evolution: The conventional Aharonov–Bohm time operator is obtained by taking the infinite-radius limit. Then, we discuss the connection between time operators, time crystals and real-space topology. We also reveal the relationship between our time operators and a -symmetric time operator. These time operators are then used to derive several energy-time uncertainty relations.Abstract We investigate time operators in the context of quantum time crystals in ring systems. A generalized commutation relation called the generalized weak Weyl relation is used to derive a class of self-adjoint time operators for ring systems with a periodic time evolution: The conventional Aharonov–Bohm time operator is obtained by taking the infinite-radius limit. Then, we discuss the connection between time operators, time crystals and real-space topology. We also reveal the relationship between our time operators and a -symmetric time operator. These time operators are then used to derive several energy-time uncertainty relations.

Journal of Physics A Mathematical and TheoreticalAug 30, 20197 citations

Time Symmetry in Operational Theories

Lucién Hardy

The standard operational probabilistic framework (within which we can formulate Operational Quantum Theory) is time asymmetric. This is clear because the conditions on allowed operations are time asymmetric. It is odd, though, because Schoedinger's equation is time symmetric and probability theory does not care about time direction. In this work we provide a time symmetric framework for operational theories in general and for Quantum Theory in particular. The clearest expression of the time asymmetry of standard Operational Quantum Theory is that the deterministic effect is unique - meaning there is only one way to ignore the future - while deterministic (i.e normalised) states are not unique. In this paper, this time asymmetry is traced back to a time asymmetric understanding of the most basic elements of an operational theory - namely the operations (or boxes) out of which circuits are built. We modify this allowing operations to have classical incomes as well as classical outcomes on these operations. We establish a time symmetric operational framework for circuits built out of operations. In particular, we demand that the probability associated with a circuit is the same whether we calculate it forwards in time or backwards in time. We do this by imposing various double properties. These are properties wherein a forward in time and a backward in time version of the same property are required. In this paper we provide a new causality condition which we call double causality.The standard operational probabilistic framework (within which we can formulate Operational Quantum Theory) is time asymmetric. This is clear because the conditions on allowed operations are time asymmetric. It is odd, though, because Schoedinger's equation is time symmetric and probability theory does not care about time direction. In this work we provide a time symmetric framework for operational theories in general and for Quantum Theory in particular. The clearest expression of the time asymmetry of standard Operational Quantum Theory is that the deterministic effect is unique - meaning there is only one way to ignore the future - while deterministic (i.e normalised) states are not unique. In this paper, this time asymmetry is traced back to a time asymmetric understanding of the most basic elements of an operational theory - namely the operations (or boxes) out of which circuits are built. We modify this allowing operations to have classical incomes as well as classical outcomes on these operations. We establish a time symmetric operational framework for circuits built out of operations. In particular, we demand that the probability associated with a circuit is the same whether we calculate it forwards in time or backwards in time. We do this by imposing various double properties. These are properties wherein a forward in time and a backward in time version of the same property are required. In this paper we provide a new causality condition which we call double causality.

arXiv:2104.00071Mar 31, 20218 citations

Time Operators

Asao Arai

Mathematical physics studiesJan 1, 20200 citations

\mathcal{PT}

-symmetric time operator. These time operators are then used to derive several energy-time uncertainty relations.