Photo tour: what is being done at the ITMO University's Laboratory of Quantum Materials

    Earlier we showed our fablab and laboratory of cyber-physical systems . Today you can look at the optical laboratory of the Faculty of Physics and Technology of the ITMO University. In the photo: a three-dimensional nanolithograph The laboratory of low-dimensional quantum materials belongs to the research center of nanophotonics and metamaterials ( MetaLab ) based on the Faculty of Physics and Technology . Its employees are studying the properties of quasiparticles.

    : plasmons, excitons, and polaritons. These studies will make it possible to create full-fledged optical and quantum computers. The laboratory is divided into several working areas covering all stages of work with low-dimensional quantum materials: sample preparation, their manufacture, characterization and optical studies.

    The first zone is equipped with everything necessary for the preparation of samples of metamaterials .

    An ultrasonic cleaner is installed to clean them, and to ensure safe operation with alcohols, a powerful hood is equipped here. Some research materials are delivered to us by partner laboratories in Finland, Singapore and Denmark.

    For sterilization of samples in the room is a drying cabinet BINDER FD Classic.Line. The heating elements inside it maintain a temperature of 10 to 300 ° C. It has a USB interface for continuous temperature monitoring throughout the experiment.

    Laboratory staff also use this camera for stress tests and aging test tests. Such experiments are necessary to understand how materials and devices behave under certain conditions: standard and extreme.

    A three-dimensional nanolithograph is installed in an adjacent room. It allows you to fabricate three-dimensional structures with a size of several hundred nanometers.

    The principle of its operation is based on the phenomenon of two-photon polymerization. In fact, it is a 3D printer that uses lasers to form an object from a liquid polymer. The polymer solidifies only at the point where the laser beam is focused.

    In the photo: three-dimensional nanolithograph

    Unlike standard lithography methods that are used to create processors and work with thin layers of materials, the two-photon polymerization method allows you to create complex three-dimensional structures. For example, these are:

    The next laboratory room is used for optical experiments.

    There is a large optical table with a length of almost ten meters, filled with numerous installations. The main elements of each installation are radiation sources (lasers and lamps), spectrometers and microscopes. One of the microscopes has three optical channels at once - upper, lateral and lower.

    It can be used to measure not only transmission and reflection spectra, but also scattering. The latter give very rich information about nanoobjects, for example, spectral characteristics and radiation patterns of nanoantennas.

    In the photo: the effect of light scattering on silicon particles.

    All equipment is located on a table with a single vibration suppression system. The radiation of any laser can be sent to any of the optical systems and microscopes with just a few mirrors and continue research.

    A gas laser with a very narrow spectrum makes it possible to conduct Raman spectroscopy experiments. The laser beam is focused on the surface of the sample, and the spectrum of scattered light is recorded by a spectrometer.

    The spectra show narrow lines corresponding to inelastic light scattering (with a change in wavelength). These peaks provide information on the crystal structure of the sample, and sometimes even on the configuration of individual molecules.

    A femtosecond laser is also installed in the room. It is capable of generating very short (100 femtoseconds - one ten-trillion part of a second) pulses of laser radiation with great power. As a result, we get the opportunity to study nonlinear optical effects: the generation of doubled frequencies and other fundamental phenomena unattainable in natural conditions.

    Our cryostat is also in the laboratory. It allows optical measurements with the same set of sources, but at low temperatures up to seven Kelvin, which is approximately -266 ° C.

    Under such conditions, a number of unique phenomena can be observed, in particular, the mode of strong coupling of light with matter, when a photon and an exciton (electron-hole pair) form a single particle - an exciton-polariton. Polaritons have great prospects in the fields of quantum computing and devices with strong nonlinear effects.

    In the photo: INTEGRA probe microscope.

    In the last room of the laboratory, we placed our diagnostic devices - a scanning electron microscope and a scanning probe microscope.. The first allows you to obtain an image of the surface of an object with high spatial resolution and to investigate the composition, structure and other properties of the surface layers of each material. To do this, he scans them with a focused beam of electrons dispersed by high voltage.

    A scanning probe microscope does the same with a probe that scans the surface of a sample. In this case, it is possible to simultaneously obtain information about the “landscape” of the surface of the sample and about its local properties, for example, electric potential and magnetization.

    Pictured: S50 Scanning Electron Microscope (EDAX)

    These instruments help us characterize samples for further optical studies.

    Projects and plans

    One of the main projects of the laboratory is the study of the hybrid states of light and matter in quantum materials - the exciton polaritons already mentioned above. A megagrant of the Ministry of Education and Science of the Russian Federation is devoted to these topics. The project is led by a leading scientist from the University of Sheffield, Maurice Shkolnik. The experimental work on the project is conducted by Anton Samusev, and the theoretical part is led by professor of the Faculty of Physics and Technology Ivan Shelykh.

    Laboratory staff are also exploring ways to transmit information using solitons. Solitons are waves that are not affected by dispersion. Due to this, the signals transmitted using solitons do not “blur” as they propagate, which allows both speed and transmission range to be increased.

    At the beginning of 2018, scientists of our University and colleagues from the university in Vladimir presented a model of a solid-state terahertz laser. The peculiarity of the development is that terahertz radiation is not "delayed" by objects made of wood, plastic and ceramics. Due to this property, the laser will be used in passenger and baggage inspection areas for quick search of metal objects. Another area of ​​applicability is the restoration of ancient works of art. The optical system will help to obtain images hidden under layers of paint or ceramics.

    Our plans are to equip the laboratory with new equipment in order to conduct even more complex studies. For example, to purchase a tunable femtosecond laser, which will significantly expand the range of materials under study. This will help in tasks related tothe development of quantum chips for next-generation computing systems.

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