Excited state control of modular quantum dot networks
Abstract
(1) Scientific objectives. The goal of this project, which spans the ModQ and FastCARS topics, is to demonstrate a new modular quantum computing architecture based on interconnected quantum dots in silicon. (2) Methods to be employed. For the ModQ portion of the program, a novel modular and scalable architecture will be demonstrated, which relies on spin shuttling via resistive top gates to connect remote quantum dot processing nodes. In contrast to schemes relying on clocked CCD arrays, this transport scheme only uses single baseband pulses, requires only a single additional layer of lithography and allows for fanout (i.e., each quantum dot node can connect to many different nodes). This implies the architecture has a higher overall connectivity when compared to conventional quantum dot arrays and even arrays incorporating CCD-based transport schemes. For the FastCARS portion of the program, a novel optical approach to control and readout silicon quantum dot qubits will be demonstrated, which are high-speed, scalable, and high-fidelity. This approach is based on the application of global optical (THz) fields, which can drive spin-selective orbital transition, enabling both single- and two-qubit operations. Moreover, these transitions can be used for quantum nondemolition readout on timescales fast compared to state-of-the-art approaches, all while requiring no local high-bandwidth control lines. Relaxing the requirement for each qubit to have a radiofrequency coaxial cable for control and readout leads to orders-of-magnitude reductions in the thermal load for quantum dot processors, which must be operated at mK temperatures, thus overcoming a key bottleneck in developing large-scale quantum processors. (3) Significance of the proposed effort to the advancement of knowledge. Through combined theory and experimental efforts, this program aims to develop faster and more efficient control of quantum dot spin qubits in a highly scalable and reconfigurable architecture by achieving the following scientific breakthroughs: (1) coherent spin-shuttling in silicon, (2) entanglement distribution in multi-node quantum dot networks, (3) efficient state preparation, and (4) fast and scalable control and readout through application of optical (THz) control fields. These advancements of knowledge are expected to push the field from few-qubit demonstrations towards practical many-qubit quantum processing devices, which are of interest to the ARO and DoD.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 27, 2023
- Source ID
- W911NF2310242
Entities
People
- Anthony Sigillito
Organizations
- Army Contracting Command
- National Security Agency
- University of Pennsylvania