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Showing 1 to 20 of 55 for “"polaron"”.
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The weakly coupled polaron
… of weakly coupled longitudinal optical polarons. By taking into consideration the contribution of the multi-phonon and the phonon-cross-exchange diagrams in the self-energy, a vertex correction has been made to the lowest order diagram. The real part and the imaginary part of the …
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Theory of polaron mobility
"Two different methods for describing the polaron-phonon system are formulated 0 These are: (1) description in terms of quasiparticle states, (2) description in terms of thermodynamic GreenYs functions~ The first approach leads naturally to an S matrix formulation of polaron transport~ The second …
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Polaron Transport in Silver-Bromide
Made available in DSpace on 2015-05-12T22:39:09Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 7500466.PDF: 2432074 bytes, checksum: fb431e44a890d72ee2d4833b2a3f8f53 (MD5) Previous issue date: 1974
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Polaron transport in silver bromide
… for a more complete theoretical treatment of the polaron problem in AgBr are made.
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Polaron transport in ionic crystals
… observed at 139 GHz by electron heating effects. Polaron effective masses were measured in a variety of materials and the results compared with previous experiments and theory. In addition, transport effects due to spin polarization were qualitatively identified in colored potassium halides. These …
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Classical Hamiltonian dynamics of a particle interacting with the vibrational modes of a one-dimensional medium
"The polaron and more generally the basic problem of a particle interacting with the vibrational modes of the local medium are important to a large range of physical processes. The complex behavior and underlying properties of polaron dynamics has been the focus of much research for many years. …
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Radio-frequency spectroscopy of ultracold atomic Fermi gases
… immersed in a sea of Fermions constitutes a polaron, which can be described by Landau's Fermi liquid theory. A critical interaction strength can be identified separating the regime of a fermionic polaron and a bosonic polaron. Radio-frequency spectroscopy of the polarized superfluid phase …
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Dimers, Trimers and their Superpositions in a Bose-Fermi Mixture
… their evolution into strongly interacting Bose polarons with hybridized dimer and trimer character when we instead immerse an impurity concentration of K into a dense quantum bath of Na. We report a novel direct observation of a heteronuclear halo trimer, consisting of two lighter Na atoms and …
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Experimental investigations of excited-state dynamics in conjugated polymers using time-resolved laser spectroscopy
… adjacent polymer chains. Finally, delocalised polaron generation in blends of the regio-regular polythiophene poly(3-dodecylthiophene-2,5-diyl) with the electron acceptor [6,6]-phenyl-C61-butyric acid methyl ester was investigated using femtosecond pump-probe spectroscopy. Both the rate and …
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From strongly-interacting Bose-Fermi mixtures to ultracold molecules
… the system realized the canonical Bose polaron quasiparticle, which is an important paradigm in condensed matter physics. We investigated the strongly-coupled Bose polaron as it approached the quantum critical regime of the Bose-Fermi mixture. Using radiofrequency spectroscopy, we probed …
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Theory of lattice effects on magnetic interactions in solids
… In the fifth chapter we examine the magnetic polaron and discuss the effect of static lattice coupling on its binding energy, and find it to further stabilize the polaron.
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Optoelectronic processes in polyfluorene ambipolar transistors
… forming a localised entity known as a polaron. The polaron has two new electronic states within the energy gap symmetrically spaced about the midgap energy. Typically two new optical transitions between the polaronic states are allowed and can be accessed with sub gap energies. In order …
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Electrical transport properties of barium titanate-based capacitor ceramics
… transport mechanism in X7R ceramic is small polaron hopping, although the possibility of combining small polaron hopping and grain boundary transmission cannot be excluded.
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Infrared absorption by localized polarons in the silver halides
… the Buimistrov-Pekar expression for the polaron self energy was evaluated in a new manner. The results showed that for coupling constants O! less than 6, the Buimistrov-Pekar formulation gives a lower value of self energy than other polaron theories. The longitudinal optical frequencies …
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Few- and Many-body Physics with Strongly Interacting Bose Gases
… of the majority bath, realising the Bose polaron scenario. Using spectroscopic and interferometric methods, we probe the response of the system to sudden ‘injection’ of impurities. We investigate the limits of the quasiparticle description for near-resonant interactions and establish the …
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Strongly interacting quantum mixtures of ultracold atoms
… Bose- Fermi problems, in particular the Bose polaron problem. Thirdly, we report on the first formation of ultracold fermionic Feshbach molecules of 23Na40K by radio-frequency association. The lifetime of the nearly degenerate molecular gas exceeds 100 ms in the vicinity of the Feshbach …
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Nonreciprocal phenomena in superconductivity
… bilayers. We predict a new bound state, spin polaron, formed by binding a doped hole with a magnon (spin flip). Spin polarons have large effective mass and are spin 3/2 quasiparticles. The mechanism for their formation is kinetic frustration, and therefore their binding energy is proportional …
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Transport properties of electrons in potassium bromide
… ,and low carrier density was developed. The polaron mass in KBr was measured for the first time using this technique. In addition the static dielectric constant for KBr was determined from 4.2 K to room temperature.
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Probing the Dynamics of Pressure- and Magnetic Field -Tuned Transitions in Strongly-Correlated Electron Systems: Raman Scattering Studies
… the magnetic susceptibility; (iii) a magnetic polaron (MP) regime, in which the development of an H = 0 spin-flip Raman response betrays the formation of magnetic polarons above the Curie temperature Tc; and (iv) a ferromagnetic metal regime, characterized by a flat electronic continuum …
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