Electromagnetic and Thermal Processes in High Temperature Superconductors; Development and Application of Electrical and Electronic Superconducting Devices.
Electronic Conductance in Strongly Correlated Systems (Manganites); Colossal Magnetoresistance; Magnetic Transport of Nano-size Granular Magnetic Structures.
Thermoluminesence and Thermoluminescent Dosimetry; Supralinearity and Efficiency of TLMaterials; Radiation Detector Physics and Applications
Single spin detection; STM of disordered surfaces; Studies of elastic properties in thenanometer scale.
Optical and structural properties of Quantum Nanostructures; III-V (arsenides and nitrides) semiconductor thin films; Quantum wells.
Noise in strongly correlated systems (Jung's Group)
To many physicist the subject of fluctuations appears esoteric and even pointless; spontaneous fluctuations seem nothing but an unwanted evil which only an unwise experimenter would encounter. In reality, noise enables a deep insight into physics of the system. Recently, we have employed noise to discriminate various resistivity states in the ferromagnetic insulating manganite La0.86Ca0.14MnO3. Different states arise due to transitions between local minima of the electronic glass potential landscape. Remarkably, freezing into the glass state is marked by the onset of non-Gaussian noise.
Magnetic Resonance on the single atom level (Manassen's Group)
In the STM image shown, observed in our lab, we see some disordered white spots. The STM does not have chemical identification capability. Such chemical identification is observed macroscopically using macroscopic magnetic resonance – both of electrons and nuclei. We develop a magnetic resonance technique on the single atom level, observed via a Larmor frequency component in the tunneling current. We identify the type of atoms under the tip using their spectrum – for example the SiC hyperfine spectrum. Preliminary results showed the observation of the nuclear transitions (NMR) with the STM.
Mechanical properties on the nm scale (Manassen's Group)
The scanning tunneling microscope is a device capable of observing an image with atomic resolution and is capable of observing physical phenomena on the atomic scale. In this study we are interested in the nm scale mechanical properties, normally studied macroscopically, which can vary in different locations on the surface. These properties are the stress and strain tensors, the elastic constants, the surface energy and stress. These values can be measured either using a external perturbation (the STM tip) or internal perturbation (a heteroepitaxial island, chemical reaction).