Coherent control of an ultrabright single spin in hexagonal boron nitride at room temperature

Abstract

Hexagonal boron nitride (hBN) exhibits as the remarkable two-dimensional (2D) material to host solid-state spins, which has the great potential to be used in quantum information including quantum network. In this application, both the optical and spin properties are curcial for single spins, however, which nevertheless are not discovered simultaneously for hBN spins yet, e.g., the negatively charged boron-vacancy defect can be coherently controlled but is not isolated due to weak optical properties, and single-defect ODMR is detected but not shown to be coherently controllable. Here, we realize an efficient method to array and isolate the single defects of hBN and find a new spin defect. This single defect emits antibunching photons with ultrahigh emission rate reaching 25MHz (corrected) and Debye-Waller factor of 0.8, and possesses the optically-controllable spin (with narrow optically-detected-magnetic-resonance linewidth) indicated by significant Rabi-oscillation and Hahn-echo experiment at room temperature. First principles calculations indicate that complexes of carbon and oxygen dopants may be the origin of the single spin defects. The probability to find optically-detectable spins by our method is 85%, which gets 21-fold enhancement compared to the traditional methods. This provides the possibility to further address the spins that can be optically-controlled, since they only take 10.5% out of the optically-detectable spins.

Quantum Emitters in Hexagonal Boron Nitride

“…Importantly, these defects are all far brighter than V B − , and some of them have been observed as single sites, including an ultrabright defect for which coherent spin control was demonstrated. 71 This makes them attractive for applications, although progress to reliably create them with control over density and position is necessary. Work is also underway to understand the limits to the spin coherence of hBN spin defects, likely related to the nuclear spin bath intrinsically present in hBN, 53,55,68 and to extend it via dynamical decoupling methods and materials engineering (e.g., isotopic purification).…”

Laser Direct Writing of Visible Spin Defects in Hexagonal Boron Nitride for Applications in Spin-Based Technologies

“…Although the carbon-related spin defect can be generated by metal organic vapor phase epitaxy (MOVPE) by controlling the gas environment, 40,41 this method is a little bit complicated, and the defects locate randomly; as for direct annealing, the generation of a spin defect with ZPL ∼ 545 nm seems more uncontrollable. 43 For further research, a key step is to find a convenient deterministic fabrication method, which is also the basis for practical applications.…”

Reflective dielectric cavity enhanced emission from hexagonal boron nitride spin defect arrays

“…12 Recent studies have shown the existence of color centers in hBN capable of spin initialization, readout, and coherent manipulation at room temperature. [13][14][15][16][17][18][19][20] The negatively charged boron vacancy (V B…”