Entanglement Generation among electron and nuclear spins of NV center in Diamond at Room Temperature

Florian Dolde, Ingmar Jakobi, Boris Naydenov +7 more

Alexander P. Nizovtsev, S. Ya. Kilin, Fedor Jelezko +4 more

In an effort to realize a two-bit processor for a quantum computer on the basis of single nitrogen-vacancy defect centers (NV centers) in diamond, the optically detected nutations of the electron spin of a single NV center in the ground state and of the nuclear spin of a 13 C atom located at a diamond lattice site nearest to the NV center are studied. The photodynamics of NV and NV + 13 C centers under different temperatures and optical excitation conditions is discussed. A seven-level model of a center excited by radiation from an Ar + laser at room temperature is proposed. On the basis of this model, the experimental spectra of optically detected electron paramagnetic and electron-nuclear double resonances of single NV and NV + 13 C centers in diamond nanocrystals, as well as experimental data on the optically detected nutations of the electron and nuclear spins of these centers caused by the actions of pulsed microwave and radiofrequency fields, respectively, are interpreted.

许丽 Xu Li, 刘阿鹏 LIU A-peng

Emre Togan

Individual nitrogen vacancy (NV) centers in diamond have recently emerged as a leading candidate for a building block for quantum information processing systems. Individual NV centers have many properties that are desirable for qubits. For example their spin states can be manipulated, initialized and measured even at room temperature. In order to build a quantum information processing system that consists of more than a single NV center, these individual NV centers have to be connected via quantum channels that distribute entanglement and allow quantum state transfer between NV centers. This thesis explores how the optical properties of the NV center can be used and manipulated to form these quantum channels. Likewise we show how the same properties can be used to better control the nuclear spin environment surrounding the NV center. We first introduce, review and experimentally study the relevant optical properties of the NV center. These quantum optical techniques are then used to experimentally demonstrate spin-photon entanglement between the electronic spin of an individual NV center and a single photon. We next demonstrate quantum interference of two photons produced by NV centers in distinct diamond samples separated by two meters. These two demonstrations pave the way for entanglement generation, leading to quantum channels, between remote NV centers. Finally we demonstrate optical cooling, real-time measurement and conditional preparation of the nuclear spin environment around an NV center using all-optical manipulation of its electronic spin. This technique can lead to better control of individual NV centers and thus more robust quantum information processing systems.

Ran Fischer, Andrey Jarmola, Pauli Kehayias +1 more

We report polarization of a dense nuclear-spin ensemble in diamond at room temperature. The method is based on the transfer of electron spin polarization of negatively charged nitrogen vacancy (NV) color centers to the nuclear spins via the excited-state level anti-crossing (ESLAC) of the center. We demonstrate polarization of 80% of the 14 N nuclear spins related to the NV centers, as well as that of 50% of the proximal 13 C nuclear spins. This work may enable polarization of the 13 C in bulk diamond, which is of interest to applications of nuclear magnetic resonance, quantum memories in hybrid quantum devices, and in sensing.

Mohsen Babamoradi, Mehdi Heidari Saani, Ahmad Ranjbar +2 more