Probabilistic quantum teleportation via thermal entanglement

Abstract

We study the probabilistic (conditional) teleportation protocol when the entanglement needed to its implementation is given by thermal entanglement, i.e., when the entangled resource connecting Alice and Bob is an entangled mixed state described by the canonical ensemble density matrix. Specifically, the entangled resource we employ here is given by two interacting spin-1/2 systems (two qubits) in equilibrium with a thermal reservoir at temperature T. The interaction between the qubits is described by a Heisenberg-like Hamiltonian, encompassing the Ising, the XX, the XY, the XXX, and XXZ models, with or without external fields. For all those models we show analytically that the probabilistic protocol is exactly equal to the deterministic one whenever we have no external field. However, when we turn on the field the probabilistic protocol outperforms the deterministic one in several interesting ways. Under certain scenarios, for example, the efficiency (average fidelity) of the probabilistic protocol is greater than the deterministic one and increases with increasing temperature, a counterintuitive behavior. We also show regimes in which the probabilistic protocol operates with relatively high success rates and, at the same time, with efficiency greater than the classical limit 2/3, a threshold that cannot be surpassed by any protocol using only classical resources (no entanglement shared between Alice and Bob). The deterministic protocol's efficiency under the same conditions is below 2/3, highlighting that the probabilistic protocol is the only one yielding a genuine quantum teleportation. We also show that near the quantum critical points for almost all those models the qualitative and quantitative behaviors of the efficiency change considerably, even at finite T.

12 pages, 8 figures, two-column, RevTex4; v2: published version with a new appendix

References in corpus (7)

• Experimental quantum teleportation
• Generalized Quantum State Sharing
• Fighting noise with noise in realistic quantum teleportation
• Probabilistic quantum teleportation in the presence of noise
• Interplay between quantum phase transitions and the behavior of quantum correlations at finite temperatures
• Generalized Quantum Telecloning
• Optimal fidelity for a quantum channel may be attained by non-maximally entangled states

Cited by in corpus (9)

• Detecting quantum critical points at finite temperature via quantum teleportation
• Detecting quantum critical points at finite temperature via quantum teleportation: further models
• Finite temperature detection of quantum critical points: a comparative study
• Finite temperature detection of quantum critical points via internal quantum teleportation
• Memory effects teleportation of quantum Fisher information under decoherence
• Competition of Direct and Indirect Sources of Thermal Entanglement in a spin star network
• Teleportation-based quantum state tomography
• Teleportation based detection of quantum critical points using small spin chains
• Quantum teleportation by utilizing helical spin chains for sharing entanglement