6533b861fe1ef96bd12c5a07

RESEARCH PRODUCT

Optimal local control of coherent dynamics in custom-made nanostructures

Eric J. HellerMario F. BorundaMario F. BorundaThomas BlasiThomas BlasiEsa RäsänenEsa RäsänenEsa Räsänen

subject

Physicsta114Field (physics)Charge (physics)Context (language use)Condensed Matter PhysicsOptimal control114 Physical sciencesElectronic Optical and Magnetic MaterialsQuantum dotCoherent controlQuantum mechanicsElectronic engineeringQuantum wellQuantum computer

description

We apply quantum optimal control theory to establish a local voltage-control scheme that operates in conjunction with the numerically exact solution of the time-dependent Schr¨ odinger equation. The scheme is demonstrated for high-fidelity coherent control of electronic charge in semiconductor double quantum dots. We find tailored gate voltages in the viable gigahertz regime that drive the system to a desired charge configuration with >99% yield. The results could be immediately verified in experiments and would play an important role in applications towards solid-state quantum computing. During the past decade, advances in the fabrication of custom-made nanostructures have allowed the observation and coherent control of single-electron dynamics in lowdimensional semiconductor systems improving the prospects and feasibility of quantum information processing. 1,2 In this context, electron transport through double quantum dots (DQDs) has been an active field of research 3 and opened access to controlling electron dynamics on the single-particle level 4 as demonstrated by several ground-breaking experiments. 5–11 Fast and accurate control of electronic states is a key requirement for solid-state quantum information processing. Here, we apply a local optimal control theory (OCT), a powerful approach to find optimized gate voltages that induce coherent transitions between electronic states in solid-state devices. The proposed schemes achieve (i) faster operation time and (ii) limits the frequencies used in the voltage profile to the experimentally accessible range, while maximizing the fidelity

https://doi.org/10.1103/physrevb.87.241303