Thermofield qubits, generalized expectations and quantum information protocols

TL;DR

This paper explores the use of thermofield dynamics for quantum information processing, proposing new protocols for quantum teleportation involving thermofield qubits at different temperatures and analyzing related quantum properties.

Contribution

It introduces a generalized thermofield dynamics framework for qubits, including teleportation protocols and analysis of quantum properties under thermal effects.

Findings

Quantum teleportation with thermofield states is feasible.

Thermofield states exhibit unique properties under thermal influence.

No-cloning and non-broadcasting theorems are extended to thermofield contexts.

Abstract

Thermofield dynamics (TFD) approach is a real time quantum field method for dealing with finite temperature quantum states in a purified version of usual density operator formalism at finite temperature. In the domain of quantum information, TFD represents a quite promising direction for dealing with qubits under thermal influence and can also be associated to Gaussian states. Here, we propose a generalized TFD mean expectation for the case of thermofield qubits considering the action of gate operators. We propose quantum teleportation protocols involving thermofield states, considering thermal-to-thermal and thermal-to-non-thermal transfering cases. In particular, we discuss the case in which Alice and Bob are at different temperatures. Action of gate operators on the result of the Mandel parameter for thermofields and on Gibbs-like density operators are also discussed. The no-cloning and non-broadcasting theorems in TFD are also considered and cases of superposed thermofield states and maps connecting thermofield vacua at different temperatures are also addressed and associated to metastable and non-equilibrium scenarios.