Effective Hamiltonian for the hybrid double quantum dot qubit

• Published in: Quantum information processing Vol. 13; no. 5; pp. 1155 - 1173
• Main Authors: Ferraro, E., De Michielis, M., Mazzeo, G., Fanciulli, M., Prati, E.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-05-2014; Springer
• Subjects: Classical and quantum physics: mechanics and fields; Data Structures and Information Theory; Exact sciences and technology; Mathematical Physics; Physics; Physics and Astronomy; Quantum computation; Quantum Computing; Quantum information; Quantum Information Technology; Quantum Physics; Spintronics; Silicon devices; Modeling; Quantum dot; Hubbard model; Quantum logics; Dynamical systems; Solid state; Quantum computing; Hamiltonians; High speed; Quantum state; Hamiltonian mechanics; Quantum information; Modelling; Exchange interactions
• ISSN: 1570-0755; 1573-1332
• DOI: 10.1007/s11128-013-0718-2

Quantum dot hybrid qubits formed from three electrons in double quantum dots represent a promising compromise between high speed and simple fabrication for solid state implementations of single-qubit and two-qubits quantum logic ports. We derive the Schrieffer–Wolff effective Hamiltonian that describes in a simple and intuitive way the qubit by combining a Hubbard-like model with a projector operator method. As a result, the Hubbard-like Hamiltonian is transformed in an equivalent expression in terms of the exchange coupling interactions between pairs of electrons. The effective Hamiltonian is exploited to derive the dynamical behavior of the system and its eigenstates on the Bloch sphere to generate qubits operation for quantum logic ports. A realistic implementation in silicon and the coupling of the qubit with a detector are discussed.