The spin Hall effect is a relativistic spin–orbit coupling phenomenon that can be used to electrically generate or detect spin currents in non-magnetic systems. In a Physical Review Letters paper we have introduced an experimental and theoretical work in this field, performed by our international Prague-Nottingham-Cambridge-Texas group. We succeeded in demonstrating electrical spin-injection into a non-magnetic semiconductor combined with electrical detection by the...
According to the theory of superconductivity put forward by Bardeen, Cooper and Schrieffer (BCS), the interaction of valence electrons with vibrations of the ions in the crystal lattice can lead to formation of bound electron pairs. These so-called Cooper pairs then condense into a superconducting state at low temperatures. The BCS theory explains the properties of the so-called conventional superconductors. In the same time, it fails for unconventional superconductors...
Conventional ferroelectricity and magnetism are chemically contraindicated in ABO3-type perovskite-structure materials. The presence of unoccupied B d orbitals and the B d – O 2p orbital hybridization are considered as causing the polar ferroelectric distortion (e.g. Ti 3d – O 2p in BaTiO3) in many perovskite ferroelectrics, while the partially filled 3d or 5f orbitals are a prerequisite for magnetism. Moreover, ferromagnetic coupling is favored if the...
We have demonstrated a new way to resolve the chemical identity of individual atoms in surface nanostructures. Our method is based on a combination of atomic force microscopy (AFM) measurements with density functional theory (DFT) calculations. This approach significantly enlarges the available means of surface and nanostructure analysis. It allows us to understand semiconductor nanostructures formed on surfaces from many aspects. Namely we can study the process of their...
Metamaterials are artificial composite structures formed by common materials in a way to exhibit new interesting electromagnetic properties. The geometrical arrangement of the composite on the microscale is of prime importance; as a rule, they rely on regularly arranged resonators with sizes and mutual distances much smaller than the targeted wavelength of the radiation. A proper choice of materials and of their arrangement can induce an unusual electromagnetic behavior....
One of the most fundamental laws of nature, the so-called no-cloning theorem, states that an unknown quantum state cannot be perfectly copied. This fact has an imminent impact on quantum information processing. For instance, it allows designing inherently secure cryptographic protocols or assures the impossibility of superluminal communication. Although perfect quantum copying is impossible, one can still investigate how well such an operation can be approximated within...
The discovery of quantum spin Hall effect and new states of solids characterized by non-trivial topology in materials with strong spin-orbit coupling lead to a substantial interest in materials with 5d electrons. Combination of the strong spin-orbit coupling, electron-electron interaction and crystal structure gives rise to unique transport, magnetic of thermodynamic properties in some of them. We have studied the temperature dependence of the magnetic order and...
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