Current Research

  • Anisotropy of electronic heat and charge transport provides an insight into critical magnetic phenomena, as revealed in non-Fermi-liquid transport properties. Measureents frequently require the lowest temperatures and use dilution refrigerator to achieve temperatures below 0.1 Kelvin degree.

  • Some superconductors exhibit avalanche - like dynamics usually associated with thermo-magnetic instabilities of the vortex lattice. We study this behavior using magneto-optical, DC and AC magnetization, transport and thermal techniques.

  • Several AC techniques covering wide magnetic field, temperature and frequency range are used to study dynamics of the magnetic transitions.

  • Precise measurements of the magnetic penetration depth are performed at low temperatures and magnetic fields up to 9 Tesla by using a tunnel-diode diode resonator.

  • Magneto-optical Faraday and Kerr effects are used to map magnetic domains on surfaces of ferromagnetic materials at variable temperature. Quantitative analysis allows studying various questions including local spin structure change during magnetic transitions (e.g. spin reorientation in Nd2Fe14B at 130 K) and precise topology of the ferromagnetic ground state.

  • NV-centers in diamond optical magnetometry utilizes completely new “quantum sensing” where we interrogate quantum states of the NV center and use it for sensing of extremely weak magnetic fields. This development will allow us to interrogate fragile states in quantum materials, such as topological insulators, unconventional superconductors and various artificial hybrid structures. Here we are specifically interested in materials and technologies relevan for Quantum Information Science (QIS), which is emerging as the next Big Effort among various agencies, DOE including.

  • Quantum critical points inside of superconducting dome of unconventional superconductors can be accessed by investigating pressure dependence of penetration depth. A novel technique to measure the penetration depth under pressure is under development.

  • The same technique is used to measure temperature-dependent dynamic magnetic response in materials exhibiting apparent transition in their ground state.

  • Direct visualization of the magnetic fields (based on magneto-optical Faraday effect) is used to study real-time formation and evolution of the intermediate state patterns in stress- and defect- free type-I superconductors.

  • Sonochemical synthesis is used to produce ceramic-based nanocomposites with ferromagnetic nanoparticles as active elements.

  • Properties of anisotropic materials are frequently averaged by formation of structural domains. Detwinning by the application of uniaxial stress enables formation of monodomain sample and enables study of intrinsic anisotropy.