Effects of peer comparisons on low-promotability tasks: Evidence from a university field experiment

Governance—the way rules are set and implemented—in many institutions is sustained through the service of groups of individuals, performing low-promotability tasks. For instance, the success of not-for-profit professional societies, civic organizations, and public universities depends on the willingness of members and employees to serve in governance. Typically service is requested by annual calls to serve. We implement and analyze a field experiment at a large public university using a randomized experimental design, to investigate whether responses to calls to serve are affected by revealing a department's service rankings among its peer departments. We find that revealing a service ranking in the lowest quartile leads to significantly higher response rates than disclosing a median and higher-than-median ranking. Second, beyond informing department heads of their departments’ service rank, directly informing individual faculty members does not have an additional effect on response rates. Third, we show that the treatment effects in the lowest serving quartile are driven by female faculty responses, even though female faculty members were no more likely than their male peers to respond to serve before the experiment. If taking on such tasks is detrimental to promotion, while important for the overall institution, this has implications for the faculty careers of women and men. We discuss potential mechanisms behind the results; formally testing these mechanisms is an area for future research

Selective coherent destruction of tunneling in a quantum-dot array

The coherent manipulation of quantum states is one of the main tasks required in quantum computation. In this paper we demonstrate that it is possible to control coherently the electronic position of a particle in a quantum-dot array. By tuning an external ac electric field we can selectively suppress the tunneling between dots, trapping the particle in a determined region of the array. The problem is treated non-perturbatively by a time-dependent Hamiltonian in the effective mass approximation and using Floquet theory. We find that the quasienergy spectrum exhibits crossings at certain field intensities that result in the selective suppression of tunneling.Comment: 4 pages, 5 figures, submitted to PRB Rapid Com

Maximal correlation between flavor entanglement and oscillation damping due to localization effects

Localization effects and quantum decoherence driven by the mass-eigenstate wave packet propagation are shown to support a statistical correlation between quantum entanglement and damped oscillations in the scenario of three-flavor quantum mixing for neutrinos. Once the mass-eigenstates that support flavor oscillations are identified as three-{\em qubit} modes, a decoherence scale can be extracted from correlation quantifiers, namely the entanglement of formation and the logarithmic negativity. Such a decoherence scale is compared with the coherence length of damped oscillations. Damping signatures exhibited by flavor transition probabilities as an effective averaging of the oscillating terms are then explained as owing to loss of entanglement between mass modes involved in the relativistic propagation.Comment: 13 pages, 03 figure

Forster signatures and qubits in optically driven quantum dot molecules

An interesting approach to achieve quantum gate operations in a solid state device is to implement an optically driven quantum gate using two vertically coupled self-assembled quantum dots, a quantum dot molecule (QDM). We present a realistic model for exciton dynamics in InGaAs/GaAs QDMs under intense laser excitation and applied electric fields. The dynamics is obtained by solutions of the Lindblad master equation. A map of the dressed ground state as function of laser energy and applied electric field exhibits rich structure that includes excitonic anticrossings that permit the identification of the relevant couplings. The optical signatures of the dipole-dipole Forster energy transfer mechanism show as splittings of several (spatially) indirect excitonic lines. Moreover, we construct a model for exciton qubit rotations by adiabatic electric field cyclic sweeps into a Forster-tunneling regime which induces level anticrossings. The proposed qubit exhibits Rabi oscillations among two well defined exciton pairs as function of the residence time at the anticrossing.Comment: Paper presented in the International Conference on Electronic Properties of Two-dimensional Systems and Modulated Semiconductor Structures Genova Magazzini del Cotone, July 15-20 200

Thermal Effects on Photon-Induced Quantum Transport

We theoretically investigate laser induced quantum transport in a two-level quantum dot attached to electric contacts. Our approach, based on nonequilibrium Green function technique, allows to include thermal effects on the photon-induced quantum transport and excitonic coherent dynamics. By solving a set of coupled integrodifferential equations, involving correlation and propagator functions, we obtain the photocurrent and the dot occupations as a function of time. The characteristic coherent Rabi oscillations are found in both occupations and photocurrent, with two distinct sources of decoherence: incoherent tunneling and thermal fluctuations. In particular, for increasing temperature the dot becomes more thermally occupied which shrinks the amplitude of the Rabi oscillations, due to Pauli blockade. Finally, due to the interplay between photon and thermal induced electron populations, the photocurrent can switch sign as time evolves and its stationary value can be maximized by tunning the laser intensity.Comment: 5 pages, 4 figure

Sedimentology and paleontology of the lower member of the Nogueras Fm (Lower Devonian) at Santa Cruz de Nogueras (Teruel, NE Spain)

An integrated sedimentological and paleontological analysis has been canted out in the lower member (d2a) of the shallow-marine Nogueras Formation (Lower Devonian, Iberian Chains). This formation represents the first carbonate-dominated and fossil-rich sedimentary unit of the Devonian of the Iberian Chains. Nine sedimentary facies, including terrigenous-clastic, mixed and carbonate facies, which are complexly intercalated at bed scale, have been characterized. Based on their sedimentary features and their lateral relationships using Markov chain analysis, two sedimentary models for the lower and upper part of d2a member have been proposed, which represent deposition in a mixed elastic-carbonate shallow marine depositional system. They include terrigenous-clastic intertidal deposits and predominant skeletal, carbonate-dominated and grain-supported facies in the high-energy shallow subtidal zone, whith a clear zonation of the skeletal components (brachiopods, bryozoans and crinoids, from shallow to relatively deep areas). Phosphate nodules, phosphatized fossils, ferruginous crusts and iron ooids, which are frequently associated with the relatively shallower bioclastic brachiopod facies, were probably linked to mineral continental sources and to remobilization in the shallow water high-energy area. The paleontological analysis shows that some of those organisms lived in protected areas of the subtidal zone, including in particular high-diversity communities of brachiopods, adapted to turbid waters with fine terrigenous suspended sediments. Se ha realizado un análisis sedimentológico y paleontológico integrado del miembro inferior (d2a) de la Formación Nogueras, que representa la primera unidad marina somera predominantemente carbonatada del Devónico de las Cadenas Ibéricas. Se han definido nueve facies sedimentarias tcrrígeno-clás ticas, mixtas y carbonatadas, que están complejamente intercaladas a escala de capa, depositadas en un sistema mixto de- trítico-carbonatado de aguas someras. En Junción de sus rasgos sedimentarios y del análisis de sus relaciones laterales mediante cadenas de Markov, se proponen dos modelos sedimentarios para la parte inferior y superior del miembro estudiado. Los dos modelos incluyen depósitos terrígenos en la zona intermareal y facies carbonatadas bioclásticas en la zona submareal somera, con una clara zonación de sus componentes esqueléticos dominantes (braquiópodos, briozoos, crinoides, desde la zona somera a la relativamente profunda). Los nodulos de fosfato, fósiles fósfatizados, costras y ooides ferruginosas frecuentes en las facies bioclasticas de braquiópodos relativamente someras, se relacionaron probablemente con aportes minerales desde el continente y retrabajamiento en la zona marina de alta energía. El análisis paleontológico muestra que algunos de estos organismos vivían en áreas protegidas de la zona submareal, incluyendo particularmente comunidades con alta diversidad de braquiópodos, adaptadas a aguas turbias con elevado sedimento terrígeno fino en suspensión