Scientific activity of the laboratory is aimed at basic radiospectroscopy research of a wide range of semiconductor and insulator materials and nanostructures and to development of new experimental techniques and modern instrumentation.
Huge experience in spectroscopy of electron paramagnetic resonance (EPR) and double resonances, such as electron-nuclear double resonance (ENDOR) and optically detected magnetic resonance (ODMR), has been accumulated by our staff during many years research both in Ioffe institute and in numerous world leading laboratories in the West. Pioneer works in the field of optically detected cyclotron resonance (ODCR) have been done in our lab.
Electron paramagnetic resonance discovered by E.K. Zavoysky in 1944 became one of the most powerful analytical techniques widely used in physics, chemistry and biology. Magnetic resonance spectroscopy, or radiospectroscoly, deals with interactions of the magnetic component of electro-magnetic field with magnetic moments of unpaired electrons and nuclear magnetic moments, which are present in the substance. Discovery of EPR initiated numerous radiospectroscopy studies of fundamental spin phenomena, biological processes, structure of intrinsic and impurity defects in condensed matter and so on.
Modern concept of EPR spectroscopy consists in increase of the operational frequency, which results in a boost of sensitivity and spectral resolution. Application of optical and electrical detection techniques for magnetic resonance allowed to reach absolute sensitivity, i.e. detection of magnetic resonance of a single molecule, a single defect, a single spin. It becomes possible to create sensors for measurements of local magnetic field, local charge and temperature with nanometer-scaled spatial resolution.
In optically detected magnetic resonance, advantages of EPR are combined with high sensitivity and spatial resolution of optical spectroscopy, which make ODMR very suitable for a study of defects, carriers and excitons in quantum wells, superlattices, quantum dots and nanocrystals. ODMR in nanostructures is one of important directions of our research. New ODMR techniques were developed on the basis of the discovered spin-dependent effects.
In our lab, new instrumentation for magnetic resonance research is designed. This work is under way in the following directions:
• Development of a line of modern EPR-ODMR spectrometers operating at 35, 78, 94, 140 GHz;
• Development of ODMR spectrometer, which combines atomic-force and confocal optical microscopes with magnetic resonance.
• A search of materials promising for a new generation of nanosensors, which are to replace diamond-based sensors by sensors based on more technologically suitable semiconductors, specifically silicon carbide