Resonant Optical Spin Initialization and Readout of Single Silicon Vacancies in 4H - SiC

Abstract

The silicon monovacancy in 4H-SiC is a promising candidate for solid-state quantum information processing. We perform high-resolution optical spectroscopy on single V2 defects at cryogenic temperatures. We find favorable low temperature optical properties that are essential for optical readout and coherent control of its spin and for the development of a spin-photon interface. The common features among individual defects include two narrow, nearly lifetime-limited optical transitions that correspond to ms= ± 3/2 and ms= ± 1/2 spin states with no discernable zero-field splitting fluctuations. Initialization and readout of the spin states is characterized by time-resolved optical spectroscopy under resonant excitation of these transitions, showing significant differences between the ±3/2 and ±1/2 spin states. These results are well-described by a theoretical model that strengthens our understanding of the quantum properties of this defect. arXiv:1811.01293v2 [cond-mat.mes-hall]

Influence of Irradiation on Defect Spin Coherence in Silicon Carbide

“…These defects can be used for room-temperature quantum metrology [13][14][15][16], including magnetometry [17][18][19][20][21][22] and thermometry [17,23]. Furthermore, single defects have been isolated, which can be used as single photon emitters [24,25], and coherent control of single defect spins [26,27] with high fidelity [28][29][30] has been realized.…”

Silicon carbide color centers for quantum applications

“…V1′ line ODMR has not been observed. Due to weak PL for the V2 emission, solid immersion lens (SIL) or nanopillars are used to achieve spin optical control and ODMR with single color centers at room temperature, otherwise optical spin control can be achieved by exciting with the laser direction orthogonal to the c axis for ensemble emission [80], as this color center dipole is primarily along the c-axis. The V1 and V1′ were recently studied as a qubit, the first proving to be a better option for spin-photon interface than V2 [73,76], which is much dimmer and not always can be generated and observed.…”

“…The V1′ line is polarized with the laser field perpendicular to the c axis and V1 with the laser field parallel to the c axis (as V2). As most SiC wafers are grown few degrees off the c-axis [80], laser excitation from the edge of the sample will increase the polarization of V1 and V2, while excitation directly on the face of the chip will provide mostly emission of the V1′ (figure 4(A)). The V1 line spin control can be achieved only at low temperatures and by in resonance excitation.…”

“…By using the V1 line of the V Si , it has been recently proven that its optical resonances are stable with near-Fourier-transform-limited linewidths, allowing single photon indistinguishability, which allows to couple its spin state selectivity to the optical transition to achieve spin-photon entanglement [76]. Single V Si have narrow, nearly lifetime-limited optical transitions that correspond to m s =±3/2 and m s =±1/2 spin states with no discernable zero-field-splitting fluctuations [80].…”

“…A defect that can support spin-photon entangled interfaces in SiC has been experimentally proved so far as the V Si V2, V1 lines [76], and DV [28,85]. They possess narrow lifetime-limited optical transitions, according to a theoretical and experimental analysis by photoluminescence excitation (PLE) [70,78,80]. Spin-selective resonant optical excitation, in particular, allows reading the spin state of SiC DV and V Si with high fidelity [62,76].…”