A Descriptive Analysis of the Appropriate Use of Cognitive Bias Terminology in Forensic Science Literature

Cognitive bias occurs without a person’s awareness and can affect decision-making abilities. In forensic science, bias can be especially detrimental to making accurate decisions about the evidence in a criminal investigation. There are many academic studies in identifying, describing, and suggesting ways to mitigate cognitive biases in forensic science. Many authors will give a known cognitive science concept a new name or create their own bias. This is a problem in the literature because nobody knows for sure how many published studies are referring to or testing the same phenomena since authors are using different definitions or terminology to describe the same concept. This study systematically identified bias terms that different domains of research use when conducting forensic science research. After identifying the bias term(s) used in each study, each error was categorized by domain (e.g., psychologists, lawyers, forensic scientists), by type of bias (e.g., confirmation bias, anchoring bias, made up bias term) and how the authors define the bias term (i.e., correct definition, incorrect definition, no definition, or made a new definition). Overall, this study shows that authors were more likely to use a correct bias term and bias definition (29%) than make up a bias term and bias definition (25%.) A majority of the authors in this study are not cognitive scientists and, therefore, are not heavily trained in cognitive terminology. The issue of the incorrect use of cognitive bias terminology is a serious one for forensic science and has yet to be noted or investigated until this preliminary analysis. The responsibility for forensic scientists who are not trained in cognitive science to understand the bias literature and to adopt the correct terminology is fundamental for proper communication among scientific professionals

A subradiant optical mirror formed by a single structured atomic layer

Efficient and versatile interfaces for the interaction of light with matter are an essential cornerstone for quantum science. A fundamentally new avenue of controlling light-matter interactions has been recently proposed based on the rich interplay of photon-mediated dipole-dipole interactions in structured subwavelength arrays of quantum emitters. Here we report on the direct observation of the cooperative subradiant response of a two-dimensional (2d) square array of atoms in an optical lattice. We observe a spectral narrowing of the collective atomic response well below the quantum-limited decay of individual atoms into free space. Through spatially resolved spectroscopic measurements, we show that the array acts as an efficient mirror formed by only a single monolayer of a few hundred atoms. By tuning the atom density in the array and by changing the ordering of the particles, we are able to control the cooperative response of the array and elucidate the interplay of spatial order and dipolar interactions for the collective properties of the ensemble. Bloch oscillations of the atoms out of the array enable us to dynamically control the reflectivity of the atomic mirror. Our work demonstrates efficient optical metamaterial engineering based on structured ensembles of atoms and paves the way towards the controlled many-body physics with light and novel light-matter interfaces at the single quantum level.Comment: 8 pages, 5 figures + 12 pages Supplementary Infomatio

Spin squeezing of high-spin, spatially extended quantum fields

Investigations of spin squeezing in ensembles of quantum particles have been limited primarily to a subspace of spin fluctuations and a single spatial mode in high-spin and spatially extended ensembles. Here, we show that a wider range of spin-squeezing is attainable in ensembles of high-spin atoms, characterized by sub-quantum-limited fluctuations in several independent planes of spin-fluctuation observables. Further, considering the quantum dynamics of an $f=1$ ferromagnetic spinor Bose-Einstein condensate, we demonstrate theoretically that a high degree of spin squeezing is attained in multiple spatial modes of a spatially extended quantum field, and that such squeezing can be extracted from spatially resolved measurements of magnetization and nematicity, i.e.\ the vector and quadrupole magnetic moments, of the quantum gas. Taking into account several experimental limitations, we predict that the variance of the atomic magnetization and nematicity may be reduced as far as 20 dB below the standard quantum limits.Comment: 18 pages, 5 figure

Absence of Anomalous Tunneling of Bogoliubov Excitations for Arbitrary Potential Barrier under the Critical Condensate Current

We derive the exact solution of low energy limit of Bogoliubov equations for excitations of Bose-Einstein condensate in the presence of arbitrary potential barrier and maximum current of condensate. Using this solution, we give the explicit expression for the transmission coefficient against the potential barrier, which shows partial transmission in the low energy limit. The wavefunctions of excitations in the low energy limit do not coincide with that of the condensate. The absence of the perfect transmission in the critical current state originates from local enhancement of density fluctuations around the potential barrier.Comment: 4 pages, 1 figur

Ground state energy of the f=1f=1 spinor Bose-Einstein condensates

We calculate, in the standard Bogoliubov approximation, the ground state energy of the spinor BEC with hyperfine spin $f=1$ where the two-body repulsive hard-core and spin exchange interactions are both included. The coupling constants characterized these two competing interactions are expressed in terms of the corresponding s-wave scattering lengths using second-order perturbation methods. We show that the ultraviolet divergence arising in the ground state energy corrections can be exactly eliminated.Comment: 14 pages, no figures, submitted to PR

Suppression and enhancement of impurity scattering in a Bose-Einstein condensate

Impurity atoms propagating at variable velocities through a trapped Bose-Einstein condensate were produced using a stimulated Raman transition. The redistribution of momentum by collisions between the impurity atoms and the stationary condensate was observed in a time-of-flight analysis. The collisional cross section was dramatically reduced when the velocity of the impurities was reduced below the speed of sound of the condensate, in agreement with the Landau criterion for superfluidity. For large numbers of impurity atoms, we observed an enhancement of atomic collisions due to bosonic stimulation. This enhancement is analogous to optical superradiance.Comment: 4 pages, 4 figure

Excitation-assisted inelastic processes in trapped Bose-Einstein condensates

We find that inelastic collisional processes in Bose-Einstein condensates induce local variations of the mean-field interparticle interaction and are accompanied by the creation/annihilation of elementary excitation. The physical picture is demonstrated for the case of three body recombination in a trapped condensate. For a high trap barrier the production of high energy trapped single particle excitations results in a strong increase of the loss rate of atoms from the condensate.Comment: 4 pages, no figure

Nonlinear Josephson-type oscillations of a driven, two-component Bose-Einstein condensate

We propose an experiment that would demonstrate nonlinear Josephson-type oscillations in the relative population of a driven, two-component Bose-Einstein condensate. An initial state is prepared in which two condensates exist in a magnetic trap, each in a different hyperfine state, where the initial populations and relative phase between condensates can be controlled within experimental uncertainty. A weak driving field is then applied, which couples the two internal states of the atom and consequently transfers atoms back and forth between condensates. We present a model of this system and investigate the effect of the mean field on the dynamical evolution.Comment: 4 pages, 3 fig

Spin correlation and Discrete symmetry in Spinor Bose-Einstein Condensates

We study spin correlations in Bose-Einstein condensates of spin 1 bosons with scatterings dominated by a total spin equal 2 channel. We show the low energy spin dynamics in the system can be mapped into an $o(n)$ nonlinear sigma model(NL$\sigma$M). $n=3$ at the zero magnetic field limit and $n=2$ in the presence of weak magnetic fields. In an ordered phase, the ground state has a hidden $Z_2$ symmetry and is degenerate under the group $[U(1)\times S^{n-1}]/Z_2$. We explore consequences of the hidden symmetry and propose some measurements to probe it.Comment: 4 pages; published version in Phys. Rev. Lett. vol 87, 080401-1(2001