Quantum information processing with defect based qubits in solids

From QCLab
Dr. Lee, Sangyun (KIST)
  • Speaker: Dr. Lee, Sangyun (KIST)
  • Date: May 30, 2017
  • Place: Science Building 433

Spins in magnetically diluted media can serve as quantum bits (qubits) for quantum information processing. Among many spin qubit candidates, defect spins in wide bandgap semiconductors have shown significant advance in recent years. One of the well-known leading contenders is the nitrogen-vacancy (NV) center in diamond. The long spin coherence time of both electron and nuclear spins even at the ambient conditions satisfies a prerequisite for qubits. The strong spin-dependent recombination in the NV center also allows an efficient spin polarization, which leads to qubit initialization and optical spin detection when the electron spin resonance is applied. The magnetic interaction between the NV center electronic spin and the adjacent nuclear spins provides a way to initialize and readout the single nuclear spins, which can be used as a long-lived quantum memory. Such quantum properties have been investigated to realize qubits, especially when the NV centers are strongly coupled to nuclear spins. Phenomenal progress so far includes quantum registers, quantum error correction, and spin-photon interfaces, to name but a few. In this presentation, I will provide a review for such demonstrations in the last decade. Because the scaling them to large-scale quantum registers is challenging, I’ll also introduce recent efforts to realize a large volume quantum network.