dorsal/arxiv
View SchemaQuantum information processing by NMR using a 5-qubit system formed by dipolar coupled spins in an oriented molecule
| Authors | Ranabir Das, Rangeet Bhattacharyya, Anil Kumar |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0409186 |
| URL | https://arxiv.org/abs/quant-ph/0409186 |
| DOI | 10.1016/j.jmr.2004.07.008 |
| Journal | Journal of Magnetic Resonance, Vol-170 (2), 310 (2004) |
Abstract
Quantum Information processing by NMR with small number of qubits is well established. Scaling to higher number of qubits is hindered by two major requirements (i) mutual coupling among qubits and (ii) qubit addressability. It has been demonstrated that mutual coupling can be increased by using residual dipolar couplings among spins by orienting the spin system in a liquid crystalline matrix. In such a case, the heteronuclear spins are weakly coupled but the homonuclear spins become strongly coupled. In such circumstances, the strongly coupled spins can no longer be treated as qubits. However, it has been demonstrated elsewhere, that the $2^N$ energy levels of a strongly coupled N spin-1/2 system can be treated as an N-qubit system. For this purpose the various transitions have to be identified to well defined energy levels. This paper consists of two parts. In the first part, the energy level diagram of a heteronuclear 5-spin system is obtained by using a newly developed heteronuclear z-cosy (HET-Z-COSY) experiment. In the second part, implementation of logic gates, preparation of pseudopure states, creation of entanglement and entanglement transfer is demonstrated, validating the use of such systems for quantum information processing.
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"abstract": "Quantum Information processing by NMR with small number of qubits is well\nestablished. Scaling to higher number of qubits is hindered by two major\nrequirements (i) mutual coupling among qubits and (ii) qubit addressability. It\nhas been demonstrated that mutual coupling can be increased by using residual\ndipolar couplings among spins by orienting the spin system in a liquid\ncrystalline matrix. In such a case, the heteronuclear spins are weakly coupled\nbut the homonuclear spins become strongly coupled. In such circumstances, the\nstrongly coupled spins can no longer be treated as qubits. However, it has been\ndemonstrated elsewhere, that the $2^N$ energy levels of a strongly coupled N\nspin-1/2 system can be treated as an N-qubit system. For this purpose the\nvarious transitions have to be identified to well defined energy levels. This\npaper consists of two parts. In the first part, the energy level diagram of a\nheteronuclear 5-spin system is obtained by using a newly developed\nheteronuclear z-cosy (HET-Z-COSY) experiment. In the second part,\nimplementation of logic gates, preparation of pseudopure states, creation of\nentanglement and entanglement transfer is demonstrated, validating the use of\nsuch systems for quantum information processing.",
"arxiv_id": "quant-ph/0409186",
"authors": [
"Ranabir Das",
"Rangeet Bhattacharyya",
"Anil Kumar"
],
"categories": [
"quant-ph"
],
"doi": "10.1016/j.jmr.2004.07.008",
"journal_ref": "Journal of Magnetic Resonance, Vol-170 (2), 310 (2004)",
"title": "Quantum information processing by NMR using a 5-qubit system formed by dipolar coupled spins in an oriented molecule",
"url": "https://arxiv.org/abs/quant-ph/0409186"
},
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