dorsal/arxiv
View SchemaStability of global entanglement in thermal states of spin chains
| Authors | Gavin K. Brennen, Stephen S. Bullock |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0406064 |
| URL | https://arxiv.org/abs/quant-ph/0406064 |
| DOI | 10.1103/PhysRevA.70.052303 |
| Journal | Physical Review A, 70, 052303 (2004). |
Abstract
We investigate the entanglement properties of a one dimensional chain of spin qubits coupled via nearest neighbor interactions. The entanglement measure used is the n-concurrence, which is distinct from other measures on spin chains such as bipartite entanglement in that it can quantify "global" entanglement across the spin chain. Specifically, it computes the overlap of a quantum state with its time-reversed state. As such this measure is well suited to study ground states of spin chain Hamiltonians that are intrinsically time reversal symmetric. We study the robustness of n-concurrence of ground states when the interaction is subject to a time reversal antisymmetric magnetic field perturbation. The n-concurrence in the ground state of the isotropic XX model is computed and it is shown that there is a critical magnetic field strength at which the entanglement experiences a jump discontinuity from the maximum value to zero. The n-concurrence for thermal mixed states is derived and a threshold temperature is computed below which the system has non zero entanglement.
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"abstract": "We investigate the entanglement properties of a one dimensional chain of spin\nqubits coupled via nearest neighbor interactions. The entanglement measure used\nis the n-concurrence, which is distinct from other measures on spin chains such\nas bipartite entanglement in that it can quantify \"global\" entanglement across\nthe spin chain. Specifically, it computes the overlap of a quantum state with\nits time-reversed state. As such this measure is well suited to study ground\nstates of spin chain Hamiltonians that are intrinsically time reversal\nsymmetric. We study the robustness of n-concurrence of ground states when the\ninteraction is subject to a time reversal antisymmetric magnetic field\nperturbation. The n-concurrence in the ground state of the isotropic XX model\nis computed and it is shown that there is a critical magnetic field strength at\nwhich the entanglement experiences a jump discontinuity from the maximum value\nto zero. The n-concurrence for thermal mixed states is derived and a threshold\ntemperature is computed below which the system has non zero entanglement.",
"arxiv_id": "quant-ph/0406064",
"authors": [
"Gavin K. Brennen",
"Stephen S. Bullock"
],
"categories": [
"quant-ph"
],
"doi": "10.1103/PhysRevA.70.052303",
"journal_ref": "Physical Review A, 70, 052303 (2004).",
"title": "Stability of global entanglement in thermal states of spin chains",
"url": "https://arxiv.org/abs/quant-ph/0406064"
},
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