{ "id": "1206.3112", "version": "v4", "published": "2012-06-14T14:05:42.000Z", "updated": "2012-11-07T03:51:47.000Z", "title": "Controllable exchange coupling between two singlet-triplet qubits", "authors": [ "Rui Li", "Xuedong Hu", "J. Q. You" ], "comment": "9 pages, 3 figures", "journal": "Phys. Rev. B 86, 205306 (2012)", "doi": "10.1103/PhysRevB.86.205306", "categories": [ "cond-mat.mes-hall", "quant-ph" ], "abstract": "We study controllable exchange coupling between two singlet-triplet qubits. We start from the original second quantized Hamiltonian of a quadruple quantum dot system and obtain the effective spin-spin interaction between the two qubits using the projection operator method. Under a strong uniform external magnetic field and an inhomogeneous local micro-magnetic field, the effective interqubit coupling is of the Ising type, and the coupling strength can be expressed in terms of quantum dot parameters. Finally, we discuss how to generate various two-qubit operations using this controllable coupling, such as entanglement generation, and controlled-NOT gate.", "revisions": [ { "version": "v4", "updated": "2012-11-07T03:51:47.000Z" } ], "analyses": { "subjects": [ "03.67.Lx", "73.21.La", "75.10.Jm" ], "keywords": [ "controllable exchange coupling", "singlet-triplet qubits", "strong uniform external magnetic field", "quadruple quantum dot system", "projection operator method" ], "tags": [ "journal article" ], "publication": { "publisher": "APS", "journal": "Physical Review B", "year": 2012, "month": "Nov", "volume": 86, "number": 20, "pages": 205306 }, "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012PhRvB..86t5306L" } } }