Abstract

The ability to spectroscopically study the spin interactions and their properties with small number of donors have greater applications in quantum information processing (QIP). The study of the magnetic resonance of the donors via electron paramagnetic resonance (EPR) is well established. However, the application of EPR is limited in the modern electronic devices with low number of spins as its sensitivity is around 10 × 10⁹ paramagnetic defects [1]. Electrically detected magnetic resonance (EDMR) spectroscopy has shown improved sensitivity than EPR by nearly 10 orders of magnitude and is considered as a powerful technique for investigating the small number of spins in any low dimensional material system and device [2]. In EDMR, the spin resonance of unpaired electrons is measured by the change in the electrical conductivity of the substrate caused by the spin dependent recombination via Pb centres, on absorption of microwaves when placed in an external magnetic field. EDMR is also suited for the electrical characterization of the spin states of the nuclear and electron spin states of donors in Si [3]. This work focusses on the establishment of a low temperature EDMR system and the characterization of lightly doped Si:P samples prepared in house via platform for nanoscale advanced materials engineering (P-NAME) tool. In the EDMR system, the cryostat used is a continuous dry He refrigerator and is combined with a 3T horizontal field split pair superconducting magnet, the pulse tube cryocooler cold head used has a cooling power of 0.5W at 4.2K, a Q band RF generator is used as the microwave source, a 405nm laser as the light source for electron hole pair formation and a gold plated brass cylindrical TE011 cavity as the resonant cavity. Structural and electronic properties of the enriched samples are studied by nanoscale secondary ion mass spectrometry (NanoSIMS), Atomic force microscopy (AFM) and transmission electron microscopy (TEM) and the defect engineering of the device via the established EDMR setup. The goal of this work is to obtain EDMR signal from the lightly doped Si samples and thereby facilitating the measurement of spin transitions of the donor electron in the Si at least 5 orders of magnitude greater than conventional EPR.

Reference

1.  Myers, K. J., et.al (2022). Journal of Applied Physics, 132(11).

2.  Akhtar, W., et.al (2015). Journal of Magnetic Resonance, 257, 94-101.

3.  Stegner, A. R., et.al, (2006). Nature Physics, 2(12), 835-838.