THIS GRANT IS A CONTINUATION OF N000141510029 Towards scalable quantum computation with electrically-gated silicon quantum dot qubits
Abstract
NSSEFF: Towards scalable quantum computation with electrically-gated silicon quantum dot qubits?, Statement of work:The tasks in this project schedule are designed to address the objectives discussed. The specific tasks for the later years will be adjusted and optimized, integrating the knowledge learned from the results of the investigations performed in the earlier years of the award.Year 1:1. Characterize theoretically ac resonant driving of hybrid qubit, focusing on how to minimize decoherence by identifying conditions for maximizing extent of ?sweet spots? or ?sweet regions? where decoherence induced by driving is minimized; 2. Develop and analyze theoretically ac excitation sequences to optimize exchange gate for hybrid qubit using STIRAP (stimulated rapid adiabatic passage);3. Perform coordinated theoretical and experimental work to increase fidelities of single qubit exchange gates, with a goal of achieving > 99% fidelity;4. Perform compressed control analysis to quantify and optimize orthogonal gating techniques in one and two-qubit devices;5. Perform experiments to characterize tunability of homogeneous dephasing times, with the aim of determining how to maximize speed of measurements used for error correction;6. Perform theoretical work to identify gate designs that increase the tunability of homogeneous dephasing times;7. Fabricate and characterize devices in Si/SiGe for which compressed control analysis predicts that fast modulation of tunnel couplings can be achieved;8. Work to fabricate quantum dot hybrid qubits in double dots in the Si/SiO2 materials system.Year 2:1. Perform compressed control analysis to optimize orthogonal control of devices with four qubits with quantum point contact readout;2. Perform compressed control analysis to optimize designs of devices for implementing multi-qubit gates for implementing surface codes;3. Investigate theoretically whether floating top-gates improve the performance of capacitively coupled two-qubit gates;4. Perform experiments, with coordinated theory, to optimize fidelity of exchange gate by modulating tunnel couplings in quantum dots designed using compressed control optimization;5. Perform theoretical work to develop two-qubit device designs with good orthogonal control together with substantial capacitive couplings between neighboring qubits;6. Investigate fidelity of exchange gates when floating top-gates to enhance capacitive couplings are incorporated into device designs;7. Fabricate quad dot (two-qubit) devices, and compare fidelities of two qubit gates achievable using tunnel couplings with those achievable using capacitive couplings between qubits;8. Compare experimental results on quadruple dots fabricated in Si/SiGe and in Si/SiO2, to assess which materials system is more promising for scale-up to larger numbers of qubits.Year 3:1. Operate and characterize quantum dot hybrid qubit using dispersive readout;2. Work to implement a STIRAP exchange gate experimentally;3. Apply compressed control to optimize device designs for up to four qubits, with a goal of simultaneously achieving high-fidelity two qubit gates and dispersive readout of each qubit;4. Investigate theoretically whether floating top-gates can be used to improve the speed of multi-qubit measurements used for surface codes;5. Perform compressed control optimization on an array of more than four qubits to optimize tunability and orthogonality of control;6. Work to develop calculational scheme for performing compressed control analysis on up to 16 qubits;7. If theoretical investigations are promising, fabricate two-qubit devices with floating top-gates and characterize capacitive couplings between qubits.Years 4 and 5:1. Fabricate and demonstrate two-qubit gates between three coupled quantum dot hybrid qubits;2. Use dispersive readout to characterize qubit operation in device with at least three quantum dot hybrid qubits;3. Characterize experimentally multi-qubit measurements performed in device with
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141612514
Entities
People
- Susan Coppersmith
Organizations
- Office of Naval Research
- United States Navy
- University of Wisconsin System