Hybrid nanophotonic-nanomagnonic SiC-YiG quantum sensor: II/dark spins quantum sensing with V2 spins and fiber based OP-PELDOR/ODMR

Abstract

<jats:p>First experiments like optically detected (OD) electron paramagnetic resonance (ODMR), photoluminescence detected RABI oscillations, and optical pumping (OP) assisted pulsed EPR measurements of T2 and T1 of V2 spins in bulk SiC, which were previously demonstrated on various home build EPR spectrometers with free space optics, are here all demonstrated for the first time using a commercial X band pulsed EPR spectrometer combined with a single optical fiber and a standard external photoluminescence setup. Quantum sensing of bulk dark spins dipolar coupled to V2 spins in SiC is also demonstrated here for the first time using single fiber based OP assisted pulsed electron electron double resonance spectroscopy (PELDOR). A spin wave resonance study of model permalloy nanostripes is also presented allowing to check the ferromagnetic nanostripes design. These experiments are first key steps towards the fiber-based integration of the recently proposed SiC-YiG quantum sensor device [J. Tribollet, Eur. Phys. J. Appl. Phys. <jats:bold>90</jats:bold>, 20102 (2020)], to a commercially available and worldwide used pulsed EPR spectrometer, with important applications expected in structural biology, surface chemistry, and quantum computing.</jats:p>

Shallow implanted SiC spin qubits used for sensing an internal spin bath and external YIG spins

“…13 This study confirmed the feasability of creating very shallow silicon vacancies near the surface, but no information about their intrinsic quantum spin coherence properties, depurated from inhomogeneous effects and ensemble effects, could be obtained, such that we cannot conclude whether this approach is detrimental or not to their usefull intrinsic quantum spin coherence properties. This is in good agreement with their well know spin hamiltonian: 1,2,4…”

“…See also cited references. 4,7,8 vacancies defects created by this implantation. This was for example demonstrated for the creation of arrays of silicon vacancies color centers at <z>= 42 nm, with a longitudinal straggling of 35 nm, using 30 keV C + ions implantation in SiC.…”

“…It is well known that silicon vacancies (VSi) color centers in silicon carbide (SiC), created far in the bulk by electron 1,2 or proton 3 irradiation, or during growth, 4 are highly quantum coherent electron spin qubits, even at room temperature. Recently, methodologies for single 4H-SiC silicon vacancies spin qubit ODMR (optically detected magnetic resonance) spectroscopy were demonstrated, for both single V1 silicon vacancies 5 and single V2 silicon vacancies, 6 further demonstrating the potential of those SiC spin qubits.…”

“…While many things have been demonstrated on bulk Vsi spin qubits, the study of shallow color centers spin qubits in SiC remains to be done. Beyond the fundamental interest, this study is also highly technologically relevant because many proposed spin based SiC quantum devices, like quantum sensors, 4,7 quantum processors 8 and single quantum photon source, 9 require quantum coherent shallow color centers spin qubits, located below the SiC surface, between few nm 4,7 and hundreds of nm, 8,9 depending on the targeted application, as illustrated on Fig. 1.…”

“…With in mind the idea of developping hybrid paramagnetic-ferromagnetic SiC based quantum processors or sensors, as recently proposed, 4,7,8 here we first demonstrate a new methodology for creating shallow VSi spin qubits located at a controlled nanoscale distance below the SiC surface by low energy ion implantation through a sacrificial SiO 2 layer, and then, we demonstrate by various magnetic resonance methods, that our shallow silicon vacancies spin qubits are 1/ coupled to an electronic spin bath, 2/ can be also coupled to the stray magnetic field of a nearby YIG ferrimagnetic thin film, and 3/, that despite the interaction with the spin bath, they remain quantum coherent, even at room temperature, which is quite promising for the development of quantum sensors and processors based on shallow Vsi spin qubits in 4H-SiC.…”