2006/11/30 by E. Räsänen, E. Rasanen, A. Castro +5 · 116 citations
Computer Science · Engineering · Physics and Astronomy · #Coherent control #Controlled NOT gate #Laser #Laser-Matter Interactions and Applications #Optics #Physics #Polarization (electrochemistry) #Quantum #Quantum Information and Cryptography #Quantum gate #Quantum mechanics #Qubit #Rabi cycle #Terahertz radiation #Terahertz technology and applications #cond-mat.other
paper · pdf · doi:10.1103/physrevlett.98.157404
published in Physical Review Letters 98(15), 157404 (American Physical Society) · Phys. Rev. Lett. (in print) (2007)
arxiv created 2007/03/16 · openalex publication_date 2007/04/13 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Complete control of single-electron states in a two-dimensional semiconductor quantum-ring model is established, opening a path into coherent laser-driven single-gate qubits. The control scheme is developed in the framework of optimal-control theory for laser pulses of two-component polarization. In terms of pulse lengths and target-state occupations, the scheme is shown to be superior to conventional control methods that exploit Rabi oscillations generated by uniform circularly polarized pulses. Current-carrying states in a quantum ring can be used to manipulate a two-level subsystem at the ring center. Combining our results, we propose a realistic approach to construct a laser-driven single-gate qubit that has switching times in the terahertz regime.