193 research outputs found
Fermi liquid parameters in 2D with spin-orbit interaction
We derive analytical expressions for the quasiparticle lifetime tau, the
effective mass m*, and the Green's function renormalization factor Z for a 2D
Fermi liquid with electron-electron interaction in the presence of the Rashba
spin-orbit interaction. We find that the modifications are independent of the
Rashba band index rho, and occur in second order of the spin-orbit coupling
alpha. In the derivation of these results, we also discuss the screening of the
Coulomb interaction, as well as the susceptibility and the self-energy in small
alpha.Comment: 9 pages, 1 fig. Corrected the result for the effective mass, and
added a section IV.B. Corrected typos and updated reference
Workplace personal exposure to respirable PM fraction: a study in sixteen indoor environments
AbstractThe present paper focuses on respirable particulate matter (RPM) measurements conducted at the breathing zone of adult volunteers in sixteen different working environments: two offices, a house, a chemical laboratory, a nonâsmoking shop, a pharmacy store, a car garage, a hairdresser's store, a photocopy store, a taxi, a gym, a mall, a restaurant, a bar, a kiosk and a school. The sixteen different cases were categorized according to the location, the type of the activities taking place indoors, the number of occupants, the proximity to heavy traffic roads, the ventilation pattern etc. According to the results, the maximum particle concentration (in average 285ÎŒg mâ3) was recorded at the hairdresser store while the minimum concentration was measured in the cases of the housewife and the employee in the nonâsmoking shop (in average 30ÎŒg mâ3). The results indicated smoking as a factor which strongly influences the exposure levels of both smokers and passive smokers. Furthermore, it was found that the building ventilation pattern comprises an important factor influencing the exposure levels especially in cases of buildings with great number of visitors (resuspension) and smoking
Toy models of crossed Andreev reflection
We propose toy models of crossed Andreev reflection in multiterminal hybrid
structures containing out-of-equilibrium conductors. We apply the description
to two possible experiments: (i) to a device containing a large quantum dot
inserted in a crossed Andreev reflection circuit. (ii) To a device containing
an Aharonov-Bohm loop inserted in a crossed Andreev reflection circuit.Comment: 5 pages, 9 figures, minor modification
Entanglement in Mesoscopic Structures: Role of Projection
We present a theoretical analysis of the appearance of entanglement in
non-interacting mesoscopic structures. Our setup involves two oppositely
polarized sources injecting electrons of opposite spin into the two incoming
leads. The mixing of these polarized streams in an ideal four-channel beam
splitter produces two outgoing streams with particular tunable correlations. A
Bell inequality test involving cross-correlated spin-currents in opposite leads
signals the presence of spin-entanglement between particles propagating in
different leads. We identify the role of fermionic statistics and projective
measurement in the generation of these spin-entangled electrons.Comment: 5 pages, 1 figur
Differences and similarities in instant countertransference towards patients with suicidal ideation and personality disorders.
Previous findings showed that suicidal patients elicit mostly negative countertransference such as distress, hopelessness, feelings of inadequacy, and apprehension, and that a concurrent personality disorder is associated with more feelings of entrapment and mistreatment, among other adverse reactions. No studies were however conducted on instant countertransference (iCT), i.e., after a single encounter, for example in an emergency setting. We aimed to evaluate the impact of suicidal ideations, self-harm and presence of personality disorders on instant Countertransference (iCT).
Caregivers rated their iCT with two validated and standardized questionnaires after a first emergency or outpatient consultation. Suicidal ideation, self-harm and personality disorders were tested as predictors for iCT in a multivariate and multilevel analysis.
Thirty caregivers rated their iCT towards 321 patients. Personality disorders and suicidal ideation, but neither recent nor past history of self-harm, predicted iCT. Common iCT included tension, lack of self-confidence and feeling of being tied. iCT specifically associated with suicidal ideation included distress, lack of hope, confusion, and sense that the patient's life had little worth. In contrast, iCT towards patients with personality disorders suggested tension in the therapeutic relationship (low affiliation with patient, anger, disappointment, devaluation).
Caregiver's characteristics were not considered in the analysis. Furthermore, while countertransference also includes unconscious phenomena, only conscious iCT was assessed.
Patients with suicidal ideation and personality disorders elicit common but also specific negative iCT. Mental health institutions need to devote specific resources (such as clinical supervision and training) to help caregivers manage their iCT
Coulomb scattering in a 2D interacting electron gas and production of EPR pairs
We propose a setup to generate non-local spin-EPR pairs via pair collisions
in a 2D interacting electron gas, based on constructive two-particle
interference in the spin singlet channel at the pi/2 scattering angle. We
calculate the scattering amplitude via the Bethe-Salpeter equation in the
ladder approximation and small r_s limit, and find that the Fermi sea leads to
a substantial renormalization of the bare scattering process. From the
scattering length we estimate the current of spin-entangled electrons and show
that it is within experimental reach.Comment: 4 page
Localization of interacting electrons in quantum dot arrays driven by an ac-field
We investigate the dynamics of two interacting electrons moving in a
one-dimensional array of quantum dots under the influence of an ac-field. We
show that the system exhibits two distinct regimes of behavior, depending on
the ratio of the strength of the driving field to the inter-electron Coulomb
repulsion. When the ac-field dominates, an effect termed coherent destruction
of tunneling occurs at certain frequencies, in which transport along the array
is suppressed. In the other, weak-driving, regime we find the surprising result
that the two electrons can bind into a single composite particle -- despite the
strong Coulomb repulsion between them -- which can then be controlled by the
ac-field in an analogous way. We show how calculation of the Floquet
quasienergies of the system explains these results, and thus how ac-fields can
be used to control the localization of interacting electron systems.Comment: 7 pages, 6 eps figures V2. Minor changes, this version to be
published in Phys. Rev.
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Concentrations of VOCs and ozone in indoor environments: A case study in two Mediterranean cities during winter period
Building materials represent the largest surfaces indoors and are the major contributors of volatile organic compounds (VOCs) in the indoor environment. This study which is conducted in the frame of BUMA project (Prioritization of Building Materials Emissions), aims at assessing the human exposure to air hazards emitted by building materials. In this study, indoor and outdoor VOCs and ozone measurements from field campaigns in two Mediterranean cities (Nicosia and Athens in winter period) are presented and discussed. The field campaigns concern weekly measurements. The campaigns were conducted in four buildings in each city (1 Public building, 1 school and 2 houses) and concern weekly measurements. Passive samplers were used for collecting VOCs and ozone. Eight (8) hydrocarbons (benzene, toluene, ethylbenzene, m,p-xylene, a-pinene, o-xylene and d-limonene), five (5) carbonyl compounds (formaldehyde, acetaldehyde, proprionaldehyde, acetone and hexanaldehyde) and ozone have been measured. Additional air exchange measurements have been conducted using tracer gas techniques. Hazardous substances such as benzene, formaldehyde and acetaldehyde present indoor concentrations that range between 1.5-10.2, 5.8-43.2 and 4.5-15 ÎŒg/m3, respectively. VOC concentration data show a considerable variability due to the different indoor emission sources, ventilation rates and outdoor environment's influence. A significant contribution to indoor measured concentrations seems to come from the building materials. Ozone outdoor concentrations are reduced substantially inside, indicating relatively strong indoor ozone sinks
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