¹³C,¹⁴N and¹⁵N ENDOR measurements on the single substitutional nitrogen centre (P1) in diamond

Abstract

New ENDOR measurements on the single substitutional nitrogen centre in diamond are reported. The CW-ENDOR mechanism utilizes cross relaxation, and measurements have been made on both 14N and 15N, as well as the first detailed 13C ENDOR study on the isotope at the natural abundance of 1.1%. The change in EPR intensity induced by driving the 13C nuclear transitions was approximately equal to 100% of the EPR intensity of the appropriate 13C hyperfine satellite. The assignment of 13C hyperfine coupling matrices with specific sites is considered, and predictions made about the signs of some of the 13C hyperfine interactions.

Suppression of spin-bath dynamics for improved coherence of multi-spin-qubit systems

“…In this physical picture, ∆E is proportional to the concentration of 13 C impurities and to the N-13 C hyperfine interaction energy, whereas ∆ N is proportional to the N concentration. Given the magnetic moments and concentrations of the N and 13 C spin impurities, and the large N-13 C hyperfine interaction in diamond 37,38 , we estimate ∆E~10 MHz and ∆ N~1 MHz for the Apollo and HPHT samples. These values imply an order of magnitude suppression of R compared with the bare electronic spin flip-flop rate ignoring N-13 C interactions (R bare~∆N ), which is consistent with our experimental results for τ c~1 /R ( Table 1).…”

All-optical hyperpolarization of electron and nuclear spins in diamond

“…1(a)]) and N 3 V 0 (vacancy with three nearest-neighbor nitrogen), in a 15 N-doped synthetic diamond with an NV − concentration <10 −3 of N s 0 . Upon illumination, neighboring 13 C and 15 N nuclei incorporated in these defect centers are spin-polarized, with 15 N polarization enhancement of >2000 over thermal equilibrium observed. Nuclear spin polarization is shown to diffuse to the bulk 13 C, leading to microwave-free OPDNP enhancements of −200 at room temperature and −500 at 240 K. We propose a possible spin polarization mechanism supported by ab initio calculations.…”

“…1(a)], and thus they possess four symmetry-related orientations within the T d diamond lattice. Both centers are S = 1/2 in the ground state (GS): unpaired electron probability density is primarily localized on the carbon atom(s) nearest neighbor to the vacancy [12], yielding small nitrogen hyperfine interactions [12,13]. The primary sample investigated was doped with 15 N (I = 1/2), and therefore each orientation of N s 0 (N 3 V 0 ) contributes a maximum of two (eight) resonance lines to an electron paramagnetic resonance (EPR) spectrum.…”

Towards a Room-Temperature Spin Quantum Bus in Diamond via Electron Photoionization, Transport, and Capture

“…As is often mistaken, this distortion is not a Jahn-Teller effect because the ground electronic state has A symmetry in the undistorted configuration [58,59]. However, analogous to a JahnTeller distortion, N 0 S undergoes temperature-dependent reorientation between its four equivalent distortions [60].…”

“…Spin parameters of N 0 S taken from Ref. [59]: orientation of defect structure or principal hyperfine axis, electronic g factor, nuclear spin of isotope, and magnetic (A ∥ , A ⊥ ) and electric (Q) hyperfine parameters.…”