Related papers: Orbital magnetic ratchet effect
We study terahertz radiation induced ratchet currents in low dimensional semiconductor structures with a superimposed one-dimensional lateral periodic potential. The periodic potential is produced by etching a grating into the sample…
Radiation-induced ratchet electric currents have been studied theoretically in graphene with a periodic noncentrosymmetric lateral potential. The ratchet current generated under normal incidence is shown to consist of two contributions, one…
The driving of charge carriers confined in a quantum well lacking the center of space inversion by an alternating electric field leads to the formation of a direct electric current. We develop a microscopic theory of such a quantum ratchet…
We report on the observation of magnetic quantum ratchet effect in metal-oxide-semiconductor field-effect-transistors on silicon surface (Si-MOSFETs). We show that the excitation of an unbiased transistor by ac electric field of terahertz…
Ratchet effect -- a {\it dc} current induced by the electromagnetic wave impinging on the spatially modulated two-dimensional (2D) electron liquid -- occurs when the wave amplitude is spatially modulated with the same wave vector as the 2D…
We report on the observation of the ratchet effect -- generation of direct electric current in response to external terahertz (THz) radiation -- in bilayer graphene, where inversion symmetry is broken by an asymmetric dual-grating gate…
We report on experimental evidence of directed electron transport, induced by external linear-polarized microwave irradiation, in a two-dimensional spatially-periodic asymmetrical system called ratchet. The broken spatial symmetry was…
A wide class of materials acquires magnetic properties due to particle interactions through exchange forces. These can be atoms and molecules composing the system itself, as in the case of numerous magnetic substances. Or these could be…
We report the observation of the terahertz-induced ratchet effect in graphene-based two-dimensional (2D) metamaterials. The metamaterial consists of a graphite gate patterned with an array of triangular antidots placed under a graphene…
We report results from a computer simulation study on the rotational ratchet effect in systems of magnetic particles interacting via dipolar interactions. The ratchet effect consists of directed rotations of the particles in an oscillating…
Electric current-induced magnetoresistance oscillations recently discovered in two-dimensional electron systems are analyzed using a microscopic scheme for nonlinear magnetotransport direct controlled by the current. The magnetoresistance…
We report on spin ratchet currents driven by terahertz radiation electric fields in a Co/Pt magnetic metamaterial formed by triangle-shaped holes forming an antidots lattice and subjected to an external magnetic field applied…
Recent experiments on re-emission of radiation and magnetotransport in photoexcited two-dimensional electron systems are theoretically analyzed. These experiments have concluded that there exists a strong correlation between the re-emitted…
Ratchets are dynamic systems where particle transport is induced by zero-average forces due to the interplay between nonlinearity and asymmetry. Generally, they rely on the effect of a strong external driving. We show that stationary…
We report on the observation and study of the magneto-ratchet effect in a graphene-based two-dimensional metamaterial formed by a graphite gate that is placed below a graphene monolayer and patterned with an array of triangular antidots. We…
We trace a simple mechanical model of a ratchet, and embed its setup in a conventional quasi-two-dimensional electron system in a semiconductor heterostructure. Expressed are two distinct microscopic mechanisms for such systems to serve as…
Persistent currents and magnetization are considered for a two-dimensional electron (or gas of electrons) coupled to various magnetic fields. Thermodynamic formulae for the magnetization and the persistent current are established and the…
We consider the orbital effect of an in-plane magnetic field on electrons in bilayer graphene, deriving linear-in-field contributions to the low-energy Hamiltonian arising from the presence of either skew interlayer coupling or interlayer…
Experimental and theoretical studies on ratchet effects in graphene with a lateral superlattice excited by alternating electric fields of terahertz frequency range are presented. A lateral superlatice deposited on top of monolayer graphene…
We report on the observation of the magnetic quantum ratchet effect in graphene with a lateral dual-grating top gate (DGG) superlattice. We show that the THz ratchet current exhibits sign-alternating magneto-oscillations due to the…