Creation of silicon vacancy in silicon carbide by proton beam writing toward quantum sensing applications

Single photon source (SPS) is a key element for quantum spintronics and quantum photonics. It is known that several color centers such as silicon vacancy ( V Si ), divacancy ( V Si V C ), carbon antisite carbon vacancy pair (C Si V C ), in silicon carbide (SiC) act as SPSs. Spin ( S = 3/2) in V Si in SiC can be manipulated even at room temperature and the intensity of its photoluminescence (PL) changes depending on the spin states ( m S = ±3/2 or m S = ±1/2). Since PL from V Si is in the near infrared region (around 900 nm), it is expected that V Si is applied to quantum sensor especially for biological or medical applications. In this review, we discuss quantum sensing based on V Si in SiC. Also, we discuss energetic particle irradiation, especially proton beam writing (PBW), in which proton microbeams with MeV range are used, as a method to create V Si in SiC since PBW can create V Si in certain locations with micrometer accuracy and this is very useful to introduce V Si in electronic devices without the degradation of their electrical characteristics.