Search results for "Observable"
showing 10 items of 634 documents
Co-existence and shell structures of several superfluids in trapped three-component Fermi mixtures
2006
We study the properties of a trapped interacting three component Fermi gas. We assume that one of the components can have a different mass from the other two. We calculate the different phases of the three component mixture and find a rich variety of different phases corresponding to different pairing channels, and simple ways of tuning the system from one phase to another. In particular, we predict co-existence of several different superfluids in the trap, forming a shell structure, and phase transitions from this mixture of superfluids to a single superfluid when the system parameters or temperature is varied. Such shell structures realize superfluids with a non-trivial spatial topology a…
High Magnetic Fields Thermodynamics of Heavy Fermion Metals
2014
In this chapter, we present the comprehensive theoretical analysis of thermodynamics of HF compounds at high magnetic fields. Such analysis permits to gain a deeper insight into the interplay of high magnetic field and temperature in suppressing and retrieving the Landau Fermi liquid state in these substances. Our analysis shows that although high magnetic fields and temperatures alter the properties of ordinary Landau quasiparticles, they survive, generating the experimentally observable anomalies in the thermodynamical quantities of HF compounds. We illustrate our theoretical findings by the example of the HF compound \(\mathrm{{YbRh_2Si_2}}\).
Jahn-Teller deformations of jellium slices
1997
Equilibrium geometries of quasi two-dimensional jellium systems are calculated in the local density approximation, closely following the “Ultimate Jellium Model” of [1]. The background charge is assumed to be fully deformable in a layer between two parallel planes, whereas the wave functions in the direction perpendicular to such a “jellium slice” are confined to their ground state. Like for jellium clusters in three dimensions [1], we find that for various system sizes, a trend towards a breaking of axial and inversion symmetries is observable.
On time-resolved approach for phonon assisted interband transitions
2015
Photoexcited dynamics of electrons and holes in two-band dielectric, with special emphasis on back reaction of phonons are developed by combining the quantum electrodynamics and Baker-Campbell-Hausdorff (BCH) canonical transformation. These methods create an explicit time-domain representation of photoinduced processes and contribute in unifying phonon-assisted description of distribution functions of electron and hole quasiparticles for the description of observable effects of photoinduced processes in dielectrics.
Particle Plasmons as Dipole Antennas: State Representation of Relative Observables
2018
The strong interactions between light and plasmons (in metal nanoparticles) allow to observe chemical and physical processes on and around the particle on nanometer length scales as well as they al...
Modeling electron dynamics coupled to continuum states in finite volumes with absorbing boundaries
2015
arXiv:1409.1689v1
Modeling dark photon oscillations in our inhomogeneous Universe
2020
A dark photon may kinetically mix with the Standard Model photon, leading to observable cosmological signatures. The mixing is resonantly enhanced when the dark photon mass matches the primordial plasma frequency, which depends sensitively on the underlying spatial distribution of electrons. Crucially, inhomogeneities in this distribution can have a significant impact on the nature of resonant conversions. We develop and describe, for the first time, a general analytic formalism to treat resonant oscillations in the presence of inhomogeneities. Our formalism follows from the theory of level crossings of random fields and only requires knowledge of the one-point probability distribution func…
Bounds on new Majoron models from the Heidelberg-Moscow experiment
1996
In recent years several new Majoron models were invented to avoid shortcomings of the classical models while leading to observable decay rates in double beta experiments. We give the first experimental half life bounds on double beta decays with new Majoron emission and derive bounds on the effective neutrino--Majoron couplings from the data of the $^{76}Ge$ HEIDELBERG--MOSCOW experiment. While stringent half life limits for all decay modes and the coupling constants of the classical models were obtained, small matrix elements and phase space integrals \cite{hir95,pae95} result in much weaker limits on the effective coupling constants of the new Majoron models.
What can be learned from the rotational motion of single molecules in a polymer melt near the glass transition?
2007
We develop a framework for the interpretation of single-molecule (SM) spectroscopy experiments of probe dynamics in a complex glass-forming system. Specifically, from molecular dynamics simulations of a single probe molecule in a coarse-grained model of a polymer melt, we show the emergence of sudden large angular reorientations (SLARs) of the SM as the mode coupling critical temperature is closely approached. The large angular jumps are intimately related to meta-basin transitions in the potential energy landscape of the investigated system and cause the appearance of stretched exponential relaxations of various rotational observables, reported in the SM literature as dynamic heterogeneity…
Bounding effective operators at the one-loop level: the case of four-fermion neutrino interactions
1994
The contributions of non-standard four-neutrino contact interactions to electroweak observables are considered at the one-loop level by using the effective quantum field theory. The analysis is done in terms of three unknown parameters: the strength of the non-standard neutrino interactions, $\tilde{F}$, an additional derivative coupling needed to renormalize the divergent contributions that appear when the four-neutrino interactions are used at the loop level and a non-standard non-derivative $Z$-${\bar\nu} \nu$ coupling. Then, the precise measurements of the invisible width of the $Z$-boson at LEP and the data on the neutrino deep-inelastic scattering yield the result $\tilde{F} = (-100 \…