dorsal/arxiv
View SchemaTwo-particle localization and antiresonance in disordered spin and qubit chains
| Authors | L. F. Santos, M. I. Dykman |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0303130 |
| URL | https://arxiv.org/abs/quant-ph/0303130 |
| DOI | 10.1103/PhysRevB.68.214410 |
Abstract
We show that, in a system with defects, two-particle states may experience destructive quantum interference, or antiresonance. It prevents an excitation localized on a defect from decaying even where the decay is allowed by energy conservation. The system studied is a qubit chain or an equivalent spin chain with an anisotropic ($XXZ$) exchange coupling in a magnetic field. The chain has a defect with an excess on-site energy. It corresponds to a qubit with the level spacing different from other qubits. We show that, because of the interaction between excitations, a single defect may lead to multiple localized states. The energy spectra and localization lengths are found for two-excitation states. The localization of excitations facilitates the operation of a quantum computer. Analytical results for strongly anisotropic coupling are confirmed by numerical studies.
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"abstract": "We show that, in a system with defects, two-particle states may experience\ndestructive quantum interference, or antiresonance. It prevents an excitation\nlocalized on a defect from decaying even where the decay is allowed by energy\nconservation. The system studied is a qubit chain or an equivalent spin chain\nwith an anisotropic ($XXZ$) exchange coupling in a magnetic field. The chain\nhas a defect with an excess on-site energy. It corresponds to a qubit with the\nlevel spacing different from other qubits. We show that, because of the\ninteraction between excitations, a single defect may lead to multiple localized\nstates. The energy spectra and localization lengths are found for\ntwo-excitation states. The localization of excitations facilitates the\noperation of a quantum computer. Analytical results for strongly anisotropic\ncoupling are confirmed by numerical studies.",
"arxiv_id": "quant-ph/0303130",
"authors": [
"L. F. Santos",
"M. I. Dykman"
],
"categories": [
"quant-ph",
"cond-mat"
],
"doi": "10.1103/PhysRevB.68.214410",
"title": "Two-particle localization and antiresonance in disordered spin and qubit chains",
"url": "https://arxiv.org/abs/quant-ph/0303130"
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