Topological Spin Qubits Based on Graphene Nanoribbons
Abstract
Identification of the Research Problem:We will develop a novel spin-based quantum information platformquantum bits, quantum logicgates, initialization, and readoutbased on the unique properties of graphene nanoribbons GNRs) thatcan be synthesized with atomic-scale precision. The GNR platform will be integrated with two otherquantum materials: LaAlO3/SrTiO3 (LAO/STO) nanostructures and graphene-based devices. Byharnessing the unique strengths of each material system, we will be able to create topologically-definedspin qubits, and manipulate them using electric fields that can be tailored with ~10 nm precision. Ourapproach takes advantage of breakthroughs in synthetic chemistry that can produce a variety of spinchain systems which can be manipulated using transverse electric fields.Three specific thrusts are envisioned, organized by intellectual proximity to the qubit itself:Thrust 1: Design, Synthesis, and Characterization of GNR Qubits. We will focus on developingthe GNR systems which possess spin chains and are amenable to integration with the LAO/STOplatform. We will work primarily with metallic spin-1/2 spin chain GNRs whose energy spectrumforms a gap under an applied transverse electric field (e.g., 5-sGNR). GNRs will be characterized byTHz and ESR-STM, time-resolved photoemission electron microscopy, and quantum transport.Thrust 2: Coupling of GNR spin qubits to environment. Interactions between spin degrees offreedom and the environment will be controlled for gating purposes, and investigated to determinemodes of decoherence. This Thrust will require a strong theoretical component to understand thenature of all possible interactions between spins and the local environment.Thrust 3: System/Architectural Design. Integration of initialization, gating, and readout of spinqubits will combine the functionality of all three subsystems. Experiments will investigate topologicalprotection of spin qubits confined between electric field nodes that are generated by LAO/STOnanoscale gate pairs. Other aspects such as quantum state transfer between nearby qubits will bedeveloped for small systems of up to four qubits.Anticipated Outcome and Impact on DoD Capabilities: The development of new quantuminformation platforms will enable new families of technologies that are based on quantum coherenceand entanglement, including sensors, quantum repeaters, and quantum information processors andcomputers.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 05, 2021
- Source ID
- N000142112537
Entities
People
- Jeremy Levy
Organizations
- Office of Naval Research
- United States Navy
- University of Pittsburgh