# Three-qubit thermal entanglement via entanglement swapping on two-qubit Heisenberg XY chains

## Abstract

In this paper, we consider the generation of a three-qubit Greenberger-Horne-Zeilinger-like thermal state by applying the entanglement swapping scheme of Zukowski et al. [Ann. N. Y. Acad. Sci. 755, 91 (1995)] to three pairs of two-qubit Heisenberg XY chains. The quality of the resulting three-qubit entanglement is studied by analyzing the teleportation fidelity, when it is used as a resource in the teleportation protocol of Karlsson et al. [Phys. Rev. A 58, 4394 (1998)]. We show that even though thermal noise in the original two-qubit states is amplified by the entanglement swapping process, we are still able to achieve nonclassical fidelities for the anisotropic Heisenberg XY chains at finitely higher and higher temperatures by adjusting the strengths of an external magnetic field. This has a positive implication on the solid-state realization of a quantum computer.

- Authors:

- Hwa Chong Institution, 673 Bukit Timah Road, Singapore 269735 (Singapore)
- (Singapore)

- Publication Date:

- OSTI Identifier:
- 20786265

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Physical Review. A; Journal Volume: 72; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevA.72.062302; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 74 ATOMIC AND MOLECULAR PHYSICS; HEISENBERG MODEL; MAGNETIC FIELDS; NOISE; QUANTUM COMPUTERS; QUANTUM ENTANGLEMENT; QUANTUM TELEPORTATION; QUBITS; SOLIDS

### Citation Formats

```
Kao, Zi Chong, Ng, Jezreel, Yeo, Ye, and Department of Physics, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260.
```*Three-qubit thermal entanglement via entanglement swapping on two-qubit Heisenberg XY chains*. United States: N. p., 2005.
Web. doi:10.1103/PHYSREVA.72.0.

```
Kao, Zi Chong, Ng, Jezreel, Yeo, Ye, & Department of Physics, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260.
```*Three-qubit thermal entanglement via entanglement swapping on two-qubit Heisenberg XY chains*. United States. doi:10.1103/PHYSREVA.72.0.

```
Kao, Zi Chong, Ng, Jezreel, Yeo, Ye, and Department of Physics, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260. Thu .
"Three-qubit thermal entanglement via entanglement swapping on two-qubit Heisenberg XY chains". United States.
doi:10.1103/PHYSREVA.72.0.
```

```
@article{osti_20786265,
```

title = {Three-qubit thermal entanglement via entanglement swapping on two-qubit Heisenberg XY chains},

author = {Kao, Zi Chong and Ng, Jezreel and Yeo, Ye and Department of Physics, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260},

abstractNote = {In this paper, we consider the generation of a three-qubit Greenberger-Horne-Zeilinger-like thermal state by applying the entanglement swapping scheme of Zukowski et al. [Ann. N. Y. Acad. Sci. 755, 91 (1995)] to three pairs of two-qubit Heisenberg XY chains. The quality of the resulting three-qubit entanglement is studied by analyzing the teleportation fidelity, when it is used as a resource in the teleportation protocol of Karlsson et al. [Phys. Rev. A 58, 4394 (1998)]. We show that even though thermal noise in the original two-qubit states is amplified by the entanglement swapping process, we are still able to achieve nonclassical fidelities for the anisotropic Heisenberg XY chains at finitely higher and higher temperatures by adjusting the strengths of an external magnetic field. This has a positive implication on the solid-state realization of a quantum computer.},

doi = {10.1103/PHYSREVA.72.0},

journal = {Physical Review. A},

number = 6,

volume = 72,

place = {United States},

year = {Thu Dec 15 00:00:00 EST 2005},

month = {Thu Dec 15 00:00:00 EST 2005}

}