Optically-Controlled Gate-Defined Quantum Dots for Quantum Information Processing.

Yanwen Wu, Xiaoqin Li, Duncan G. Steel +2 more

Cornelis Jacobus van Diepen, Pieter T. Eendebak, Bruno T. Buijtendorp +5 more

Semiconductor quantum dot arrays defined electrostatically in a 2D electron gas provide a scalable platform for quantum information processing and quantum simulations. For the operation of quantum dot arrays, appropriate voltages need to be applied to the gate electrodes that define the quantum dot potential landscape. Tuning the gate voltages has proven to be a time-consuming task, because of initial electrostatic disorder and capacitive cross-talk effects. Here, we report on the automated tuning of the inter-dot tunnel coupling in gate-defined semiconductor double quantum dots. The automation of the tuning of the inter-dot tunnel coupling is the next step forward in scalable and efficient control of larger quantum dot arrays. This work greatly reduces the effort of tuning semiconductor quantum dots for quantum information processing and quantum simulation.

Lucio Robledo, J. M. Elzerman, Gregor Jundt +4 more

Conditional quantum dynamics, where the quantum state of one system controls the outcome of measurements on another quantum system, is at the heart of quantum information processing. We demonstrate conditional dynamics for two coupled quantum dots, whereby the probability that one quantum dot makes a transition to an optically excited state is controlled by the presence or absence of an optical excitation in the neighboring dot. Interaction between the dots is mediated by the tunnel coupling between optically excited states and can be optically gated by applying a laser field of the right frequency. Our results represent substantial progress toward realization of an optically effected controlled-phase gate between two solid-state qubits.

Li, Hai-Ou, Yao +4 more

Huan Song, Tatsuya Usuki

Hai-Ou Li, Bing Yao, Tao Tu +1 more

During the past few years, researchers have made significant progress on quantum information processing in gate controlled semiconductor quantum dots. We review the global research efforts, including works by our group, which provides pathways towards applications in quantum computation.