Quantum Phase Transitions
... but will instead describe second-order phase transitions at the absolute zero of temperature. Such transitions are driven by quantum fluctuations mandated by the Heisenberg uncertainty principle: one can imagine moving across the quantum critical point by effectively “tuning the value of Planck’s co ...
... but will instead describe second-order phase transitions at the absolute zero of temperature. Such transitions are driven by quantum fluctuations mandated by the Heisenberg uncertainty principle: one can imagine moving across the quantum critical point by effectively “tuning the value of Planck’s co ...
... al., 2010) for a similarly motivated study), not the dynamics of an electron that is subject to an external field (Ahrens et al., 2012).Then we will also show how a pair of electron and positron annihilate each other. In this connection, we break away from “the Dirac’s sea of electrons with negative ...
Paper
... lithium value. We verified that, in these samples, extending the thermalization time at the end of evaporation up to 10 s did not lower the lithium temperature any farther. The reasons for the observed temperature discrepancy are worthy of further investigation. Simple spatial separation of the two ...
... lithium value. We verified that, in these samples, extending the thermalization time at the end of evaporation up to 10 s did not lower the lithium temperature any farther. The reasons for the observed temperature discrepancy are worthy of further investigation. Simple spatial separation of the two ...
Quantizing charged magnetic domain walls: Strings on a lattice
... models for doped Mott-Hubbard insulators with short-range ~on-site! Coulomb interactions only.3 As is well known, the motion of a hole in an antiferromagnetic background is hampered by the spin order. In domain walls the holes still have room to fluctuate, so that their kinetic energy is low, while ...
... models for doped Mott-Hubbard insulators with short-range ~on-site! Coulomb interactions only.3 As is well known, the motion of a hole in an antiferromagnetic background is hampered by the spin order. In domain walls the holes still have room to fluctuate, so that their kinetic energy is low, while ...
Document
... • in experiments with the photoelectric effect, it was observed that there was a maximum wavelength for electrons to be emitted called the threshold frequency regardless of the intensity ...
... • in experiments with the photoelectric effect, it was observed that there was a maximum wavelength for electrons to be emitted called the threshold frequency regardless of the intensity ...
Seafloor Spreading
... surrounding mantle material, is forced toward the surface of the crust along an ocean ridge. As the two sides of the ridge spread apart, the rising magma fills the gap that is created. When the magma solidifies, a small amount of new ocean floor is added to Earth’s surface. ...
... surrounding mantle material, is forced toward the surface of the crust along an ocean ridge. As the two sides of the ridge spread apart, the rising magma fills the gap that is created. When the magma solidifies, a small amount of new ocean floor is added to Earth’s surface. ...
Magnetic susceptibility in MRI
... Four different types of behaviour may be distinguished: Diamagnetism: χ is negative and of the order of 10-6. Paramagnetism: χ is positive and typically in the range 10-5-10-3. Superparamagnetism: appears in small ferromagnetic nanoparticles. Their magnetic susceptibility is much larger than t ...
... Four different types of behaviour may be distinguished: Diamagnetism: χ is negative and of the order of 10-6. Paramagnetism: χ is positive and typically in the range 10-5-10-3. Superparamagnetism: appears in small ferromagnetic nanoparticles. Their magnetic susceptibility is much larger than t ...
Disorder-induced order with ultra-cold atoms
... system with a continuous symmetry such as the classical isotropic ferromagnetic XY model. In this model, neighboring spins tend to align, at zero temperature, between themselves within a preferential plane, the XY plane spanned by the x and y axis. For this kind of system yielding a continuous symet ...
... system with a continuous symmetry such as the classical isotropic ferromagnetic XY model. In this model, neighboring spins tend to align, at zero temperature, between themselves within a preferential plane, the XY plane spanned by the x and y axis. For this kind of system yielding a continuous symet ...
Ferromagnetism
Not to be confused with Ferrimagnetism; for an overview see Magnetism.Ferromagnetism is the basic mechanism by which certain materials (such as iron) form permanent magnets, or are attracted to magnets. In physics, several different types of magnetism are distinguished. Ferromagnetism (including ferrimagnetism) is the strongest type: it is the only one that typically creates forces strong enough to be felt, and is responsible for the common phenomena of magnetism in magnets encountered in everyday life. Substances respond weakly to magnetic fields with three other types of magnetism, paramagnetism, diamagnetism, and antiferromagnetism, but the forces are usually so weak that they can only be detected by sensitive instruments in a laboratory. An everyday example of ferromagnetism is a refrigerator magnet used to hold notes on a refrigerator door. The attraction between a magnet and ferromagnetic material is ""the quality of magnetism first apparent to the ancient world, and to us today"".Permanent magnets (materials that can be magnetized by an external magnetic field and remain magnetized after the external field is removed) are either ferromagnetic or ferrimagnetic, as are other materials that are noticeably attracted to them. Only a few substances are ferromagnetic. The common ones are iron, nickel, cobalt and most of their alloys, some compounds of rare earth metals, and a few naturally-occurring minerals such as lodestone.Ferromagnetism is very important in industry and modern technology, and is the basis for many electrical and electromechanical devices such as electromagnets, electric motors, generators, transformers, and magnetic storage such as tape recorders, and hard disks.