Femtosecond Optics Laboratories for Nanotechnology

Investigation of the possibility of optical control of the state of magnetization and polarization in materials using femtosecond laser pulses by coherent quantum control of magnons and phonons for a new generation of electronic devices for high-speed information processing and storage.

Investigation of the effect of various types of defects on the electronic and optical properties of two-dimensional semiconductors and devices based on them. To achieve this goal, the project developed methods for creating two-dimensional semiconductors based on transition metal dichalcogenides (TPM) of variable composition and thickness, as well as methods for creating defects of various types. Work was carried out on the search for new 2D semiconductors, heterostructures based on them, and methods for their production were developed. Optical properties (reflection and absorption spectra, luminescence spectra during single-photon and two-photon pumping, and second harmonic generation) in the obtained samples were studied depending on the phase composition, polytypes, and thickness, as well as the presence of defects. The kinetics of relaxation of photoexcited charge carriers over a wide time range has been studied experimentally and theoretically. Exciton and transport properties were studied, as well as the possibilities of creating electronic devices based on DPM monolayers.

Determination of conditions and physical mechanisms for remote ultrafast state switching of a two-bit system with a picosecond terahertz pulse in order to create a platform for low-dissipative functional elements of information technology devices operating at terahertz frequencies. Switching of ferroics (ferroelectrics, multiferroics, ferro-, ferri-, antiferromagnets) between two stable bit states is the basic principle of modern data storage technology. For most applications, the most important parameters are the heat dissipation on the device, and their performance. The search for a conceptually new way to control the ferroid state of a medium with the lowest possible heat generation and in the shortest possible time is a new problem in fundamental research of condensed media. Such control can only be achieved by using short electromagnetic pulses. At the same time, switching initiated by a pulse with photon energy in millielectronvolts and subpicosecond duration, that is, an almost single pulse of THz radiation, promises the fastest and least dissipative way to control the ferroid order parameter. Switching processes are fundamentally nonlinear, and it requires the development of ways to switch the system to anharmonic mode. In this regard, the project is supposed to solve the following urgent tasks: 1. Experimental determination of the conditions and observation of the processes of excitation of anharmonicity of ferroelectric and magnetic order parameters by a terahertz pulse. 2. Experimental and theoretical determination of the conditions for the transition of the excitation mode of anharmonic phonons and magnons by a terahertz pulse to the switching mode of the corresponding order parameter. 3. Determination of energy dissipation in the studied processes.

Development of the physical and technological foundations for the creation of new highly efficient polarization-sensitive devices for nano- and optoelectronics (photodetectors and phototransistors) based on graphene-like semiconductors. - modeling the characteristics of ordered plasmonic structures located on two-dimensional graphene-like semiconductors and evaluating optimal parameters for creating highly efficient nanoelectronics devices based on them; - development of technological techniques and techniques for creating ordered plasmonic structures on the surface of two-dimensional graphene-like semiconductors and the creation of photodetectors and phototransistors based on them; - experimental study of the main operating characteristics of the created experimental devices: volt-ampere characteristics, mobility of charge carriers, photoconductivity, spectral photosensitivity, presence of resonant optical peaks, polarization sensitivity;

Development and creation of magnetoelectric materials based on molecular and organometallic coordination polymers, which can be an alternative to currently actively researched single-phase and multiphase magnetoelectric systems, in particular, based on transition metal oxides. For the successful implementation of the project, a multi-stage strategy for the development and synthesis of advanced magnetoelectric molecular systems, as well as an innovative approach to the study of synthesized materials, is proposed.

Development of the physical and technological foundations for the creation of new highly efficient spintronic THz band emitters with the ability to control terahertz polarization through the use of spin effects in (hetero)structures are magnetic/non-magnetic material. - determination of optimal structural and geometric parameters of the created spintronic radiators and detectors to achieve the greatest efficiency of their operation through the use of optical and THz interference effects; - development of technological techniques and techniques for creating controlled terahertz radiators based on hybrid materials: two-dimensional transition metal dichalcogenides/magnetic (spintronic) structure; - experimental study of the performance characteristics of the created samples of experimental spintronic generators and detectors of THz radiation: the amplitude and width of the spectrum of THz radiation generated, the parameters for controlling the direction of polarization of THz radiation, the amplitude and width of THz radiation generated, spectral sensitivity, signal-to-noise ratio.