Medical Physics
... Evacuated glass envelope containing a cathode and an anode Electrons are released from the cathode by thermionic emission and are focussed into a beam and accelerated towards the anode by a very high voltage electric field An incident electron will be slowed down by interacting with the nucleus of a ...
... Evacuated glass envelope containing a cathode and an anode Electrons are released from the cathode by thermionic emission and are focussed into a beam and accelerated towards the anode by a very high voltage electric field An incident electron will be slowed down by interacting with the nucleus of a ...
Unveiling the quantum critical point of an Ising chain
... Quantum phase transitions occur at zero temperature upon variation of some nonthermal control parameters. The Ising chain in a transverse field is a textbook model undergoing such a transition, from ferromagnetic to paramagnetic state. This model can be exactly solved by using a Jordan-Wigner transf ...
... Quantum phase transitions occur at zero temperature upon variation of some nonthermal control parameters. The Ising chain in a transverse field is a textbook model undergoing such a transition, from ferromagnetic to paramagnetic state. This model can be exactly solved by using a Jordan-Wigner transf ...
Phys. Rev. Applied 2, 024002
... η ≪ 1 and contribute to OSP [11]. Although there is a temperature dependence in the incoherent hole spin-flip rate γ hSF [10,22,23], this effect is rendered negligible by the much faster optical decay channel, i.e., γ op ≫ γ hSF . Another temperature-insensitive parameter is the coherent coupling of ...
... η ≪ 1 and contribute to OSP [11]. Although there is a temperature dependence in the incoherent hole spin-flip rate γ hSF [10,22,23], this effect is rendered negligible by the much faster optical decay channel, i.e., γ op ≫ γ hSF . Another temperature-insensitive parameter is the coherent coupling of ...
Quantum Hall ferromagnet at high filling factors: A magnetic
... up and down Landau levels, shows a universal behavior versus both temperature and electron density after judicious rescaling.14,15,5 Our experiments also confirms a collapse of the exchange-enhanced spin gap with decreasing magnetic field 共Sec. IV B兲. For a quantitative experimental description, par ...
... up and down Landau levels, shows a universal behavior versus both temperature and electron density after judicious rescaling.14,15,5 Our experiments also confirms a collapse of the exchange-enhanced spin gap with decreasing magnetic field 共Sec. IV B兲. For a quantitative experimental description, par ...
Solid State Physics (I)
... • Definition 1: Periodic structure form by infinite number of points in the space. The distribution of other points in space, observed from any of the points, is exactly the same. • Definition 2: In a 3-D lattice, the position vector of one of the points can be written as the linear combination of t ...
... • Definition 1: Periodic structure form by infinite number of points in the space. The distribution of other points in space, observed from any of the points, is exactly the same. • Definition 2: In a 3-D lattice, the position vector of one of the points can be written as the linear combination of t ...
mossbauer - Institute of Particle and Nuclear Physics
... solid. It is a solid-state equivalent of Planck's law of black body radiation, where one treats electromagnetic radiation as a gas of photons in a box. Debye treats the vibrations of the atomic lattice (heat) as phonons in a box (the box being the solid). Debye temperature is the temperature of a cr ...
... solid. It is a solid-state equivalent of Planck's law of black body radiation, where one treats electromagnetic radiation as a gas of photons in a box. Debye treats the vibrations of the atomic lattice (heat) as phonons in a box (the box being the solid). Debye temperature is the temperature of a cr ...
Test 1 w/answers
... NaOH solution higher, lower, or the same as the osmotic pressure of the NaCl solution? Explain. Vapor pressures are the same because the concentrations are the same and the vant Hoff numbers are the same 20.00 g / 40.0 g/mol = 0.500 mol NaOH ...
... NaOH solution higher, lower, or the same as the osmotic pressure of the NaCl solution? Explain. Vapor pressures are the same because the concentrations are the same and the vant Hoff numbers are the same 20.00 g / 40.0 g/mol = 0.500 mol NaOH ...
Geometrical frustration
In condensed matter physics, the term geometrical frustration (or in short: frustration) refers to a phenomenon, where atoms tend to stick to non-trivial positions or where, on a regular crystal lattice, conflicting inter-atomic forces (each one favoring rather simple, but different structures) lead to quite complex structures. As a consequence of the frustration in the geometry or in the forces, a plenitude of distinct ground states may result at zero temperature, and usual thermal ordering may be suppressed at higher temperatures. Much studied examples are amorphous materials, glasses, or dilute magnets.The term frustration, in the context of magnetic systems, has been introduced by Gerard Toulouse (1977). Indeed, frustrated magnetic systems had been studied even before. Early work includes a study of the Ising model on a triangular lattice with nearest-neighbor spins coupled antiferromagnetically, by G. H. Wannier, published in 1950. Related features occur in magnets with competing interactions, where both ferro- as well as antiferromagnetic couplings between pairs of spins or magnetic moments are present, with the type of interaction depending on the separation distance of the spins. In that case commensurability, such as helical spin arrangements may result, as had been discussed originally, especially, by A. Yoshimori, T. A. Kaplan, R. J. Elliott, and others, starting in 1959, to describe experimental findings on rare-earth metals. A renewed interest in such spin systems with frustrated or competing interactions arose about two decades later, beginning in the 70s of the 20th century, in the context of spin glasses and spatially modulated magnetic superstructures. In spin glasses, frustration is augmented by stochastic disorder in the interactions, as may occur, experimentally, in non-stoichiometric magnetic alloys. Carefully analyzed spin models with frustration include the Sherrington-Kirkpatrick model, describing spin glasses, and the ANNNI model, describing commensurability magnetic superstructures.