Graphene plasmonics: A platform for strong light
... potential of this atomic monolayer is emphasized by its remarkably high absorption 27,28 ≈ πα ≈ 2.3%, where α = e2 /h̄c ≈ 1/137 is the fine-structure constant. Moreover, the linear dispersion of the Dirac fermions enables broadband applications, in which electric gating can be used to induce dramati ...
... potential of this atomic monolayer is emphasized by its remarkably high absorption 27,28 ≈ πα ≈ 2.3%, where α = e2 /h̄c ≈ 1/137 is the fine-structure constant. Moreover, the linear dispersion of the Dirac fermions enables broadband applications, in which electric gating can be used to induce dramati ...
Quantifying particle motion under force fields in
... Figure 1. If the conductivity and permittivity of particle and surrounding medium at different frequencies are found, the relationship between the real CM factor and frequency could be plotted. When the CM factor equals to zero, the frequency is called crossover frequency. The magnitude of DEP force ...
... Figure 1. If the conductivity and permittivity of particle and surrounding medium at different frequencies are found, the relationship between the real CM factor and frequency could be plotted. When the CM factor equals to zero, the frequency is called crossover frequency. The magnitude of DEP force ...
Interaction between Atomic Ensembles and Optical
... quantum memories for light (Black et al., 2005b; Simon et al., 2007a,b; Tanji et al., 2009; Thompson et al., 2006). Many of the above applications make use of atomic ensembles rather than single atoms, in which case the complete quantum description of the ensemble–cavity interaction is nontrivial as ...
... quantum memories for light (Black et al., 2005b; Simon et al., 2007a,b; Tanji et al., 2009; Thompson et al., 2006). Many of the above applications make use of atomic ensembles rather than single atoms, in which case the complete quantum description of the ensemble–cavity interaction is nontrivial as ...
An experimental and theoretical guide to strongly interacting
... by the combination with ultracold atomic gases. The availability of commercial high power diode laser systems allow for efficient excitation into electronically highly excited states with excellent frequency resolution. Here the major motivation behind many experiments is to make use of the strong i ...
... by the combination with ultracold atomic gases. The availability of commercial high power diode laser systems allow for efficient excitation into electronically highly excited states with excellent frequency resolution. Here the major motivation behind many experiments is to make use of the strong i ...
RF Cavities - CERN Accelerator School
... The beam current “loads” the generator, in the equivalent circuit this appears as a resistance in parallel to the shunt impedance. If the generator is matched to the unloaded cavity, beam loading will cause the accelerating voltage to decrease. ...
... The beam current “loads” the generator, in the equivalent circuit this appears as a resistance in parallel to the shunt impedance. If the generator is matched to the unloaded cavity, beam loading will cause the accelerating voltage to decrease. ...
Signature of non-Newtonian orbits in ray
... the geometric optics limit, it is possible to assign rays to wave fronts. Reflection and transmission at sharply defined interfaces then give rise to the phenomenon of ray splitting. Ray splitting is universal. It occurs, e.g., in optics when a light ray encounters the interface between two differen ...
... the geometric optics limit, it is possible to assign rays to wave fronts. Reflection and transmission at sharply defined interfaces then give rise to the phenomenon of ray splitting. Ray splitting is universal. It occurs, e.g., in optics when a light ray encounters the interface between two differen ...
JavaGenes: Evolving Molecular Force Field Parameters
... a GA scaffolding is done by representing the force field parameters as a ragged twodimensional array of double precision floating point numbers. The first dimension represents the two- or three-body terms of the potential function, and the ragged second dimension represents the parameters. A ragged ...
... a GA scaffolding is done by representing the force field parameters as a ragged twodimensional array of double precision floating point numbers. The first dimension represents the two- or three-body terms of the potential function, and the ragged second dimension represents the parameters. A ragged ...
Casimir effect
In quantum field theory, the Casimir effect and the Casimir–Polder force are physical forces arising from a quantized field. They are named after the Dutch physicist Hendrik Casimir.The typical example is of two uncharged metallic plates in a vacuum, placed a few nanometers apart. In a classical description, the lack of an external field means that there is no field between the plates, and no force would be measured between them. When this field is instead studied using the QED vacuum of quantum electrodynamics, it is seen that the plates do affect the virtual photons which constitute the field, and generate a net force—either an attraction or a repulsion depending on the specific arrangement of the two plates. Although the Casimir effect can be expressed in terms of virtual particles interacting with the objects, it is best described and more easily calculated in terms of the zero-point energy of a quantized field in the intervening space between the objects. This force has been measured and is a striking example of an effect captured formally by second quantization. However, the treatment of boundary conditions in these calculations has led to some controversy.In fact, ""Casimir's original goal was to compute the van der Waals force between polarizable molecules"" of the metallic plates. Thus it can be interpreted without any reference to the zero-point energy (vacuum energy) of quantum fields.Dutch physicists Hendrik B. G. Casimir and Dirk Polder at Philips Research Labs proposed the existence of a force between two polarizable atoms and between such an atom and a conducting plate in 1947, and, after a conversation with Niels Bohr who suggested it had something to do with zero-point energy, Casimir alone formulated the theory predicting a force between neutral conducting plates in 1948; the former is called the Casimir–Polder force while the latter is the Casimir effect in the narrow sense. Predictions of the force were later extended to finite-conductivity metals and dielectrics by Lifshitz and his students, and recent calculations have considered more general geometries. It was not until 1997, however, that a direct experiment, by S. Lamoreaux, described above, quantitatively measured the force (to within 15% of the value predicted by the theory), although previous work [e.g. van Blockland and Overbeek (1978)] had observed the force qualitatively, and indirect validation of the predicted Casimir energy had been made by measuring the thickness of liquid helium films by Sabisky and Anderson in 1972. Subsequent experiments approach an accuracy of a few percent.Because the strength of the force falls off rapidly with distance, it is measurable only when the distance between the objects is extremely small. On a submicron scale, this force becomes so strong that it becomes the dominant force between uncharged conductors. In fact, at separations of 10 nm—about 100 times the typical size of an atom—the Casimir effect produces the equivalent of about 1 atmosphere of pressure (the precise value depending on surface geometry and other factors).In modern theoretical physics, the Casimir effect plays an important role in the chiral bag model of the nucleon; in applied physics, it is significant in some aspects of emerging microtechnologies and nanotechnologies.Any medium supporting oscillations has an analogue of the Casimir effect. For example, beads on a string as well as plates submerged in noisy water or gas illustrate the Casimir force.