Department of Surface and Nanostructures Physics

Research topics 

• Structural, electronic, magnetic and optical properties of low dimensional systems (surfaces, interfaces, thin films, atomic chains and wires, quantum islands and quantum dots).
• Quantum phenomena in nanostructures (surface diffusion, self-organization, quantum confinement and quantum size effect, spin and orbital nanomagnetism, charge and spin transport, ...).
• Novel 2D materials (graphene, silicene, antimonene and other Xenes, topological insulators, ...), their functionalization and applications for X-tronics, green energy and CO2 reduction, ...
• 1D systems (metallic atomic chains and nanostructures on stepped (vicinal) Si surfaces).
• Molecular structures on crystal surfaces.

Eperimental methods

• Scanning Tunneling Microscopy (STM) and Scanning Tunneling Spectroscopy (STS).
• Reflection High Electron Energy Diffraction (RHEED).
• Low Energy Electron Diffraction (LEED).
• Low Energy Electron Microscopy (LEEM, SPLEEM).
• Si surface with nanostructures electrical conductivity.
• Angle and Spin Resolved Photoelectron Spectroscopy (ARPES, SARPES).
• Differential Reflectance Spectroscopy (DRS)

Theoretical methods

• Ab-initio Density Functional Theory (DFT).
• Model Hamiltonian calculations within tight binding (TB) approach.

Nanostructures and metallic quantum wells are grown in an UHV (Ultra High Vacuum) conditions by atom vapor deposition with help of selfassembling and epitaxy processes on atomically clean, well oriented crystalline Si surfaces. Metallic atomic chains are produced on vicinal Si surfaces.

Electrical conductivity of metallic quantum wells is since long time our research topic. Our laboratory is one of few in the world where galvanomagnetic properties of the metallic quantum wells are studied. Measurements are performed in UHV environment at low temperatures starting from about 3K. 

To study details of electron band structure of surface nanostructures we use electron photoemission (ARPES) methods. The UHV MICROPROBE (OMICRON) system is equipped with UV lamp (SPECS) capable producing of intense polarized light with quanta energy of 21.2 eV. Electron energy and momentum distribution is measured with hemispherical analyzer PHOIBOS 150 (SPECS) with a micro-channel plate (MCP) detector. Attached Mott detector allows performing spin-resolved photoemission measurements.

Atomic chains on the silicon surface. Image from a scanning tunneling microscope. 

Crystal surface structure and its reconstructions upon sub-monolayer metal deposition are investigated with STM and RHEED techniques. The microscope allows performing measurements of the sample kept from helium temperatures up to several hundreds K. Atomic resolution of the microscope allows trace single atoms and the STM spectroscopic working mode gives insight into electronic nature of the sample. The STM VT (OMICRON) together with RHEED apparatus form powerful instrument for study of electronic and structural properties of nanostructures.