arXiv subjects

F. V. Kowalski

Publications and source records attributed to F. V. Kowalski.

13 recordsLinked to original sources

arXiv2024

Collective behavior in quantum interference: an alternative superposition principle

An interferometer in which all of its components are treated as quantum bodies is examined with the standard interpretation and with a model in which its uncoupled spatially separated components act collectively. These models utilize superposition principles that differ when applied to systems composed of three or more bodies. Interferometric disparities between them involving frequency shifts and recoil are shown to be difficult to measure. More pronounced discrepancies involve correlated interference. The collective model is shown to provide a missing connection between quantum and semiclassical theories. Scattering from an entangled state, which cannot be divided into disjoint parts, is discussed in relation to collective recoil. Collective scattering is shown to be a viable alternative to the standard model, thereby providing insight into constructing tests of the superposition principle in systems with three or more bodies.

quant-ph↗

arXiv2024

Threshold in quantum correlated interference for a particle interacting with two scatterers

Correlated interference is calculated for a microscopic particle retro-reflecting from two spatially separated scatterers that are free to move, all three of which are treated as quantum bodies: the positions of the particle traversing this one-dimensional interferometer and those of the interferometer components are all uncertain. Interference in a measurement of only the particle is shown to disappear for microscopic yet appear for mesoscopic scatterers, contrary to that of a quantum-classical transition. A measurement of this threshold can verify quantum correlations in many-body systems by measuring only the retro-reflected microscopic particle. The decoherence of a mesoscopic scatterer is determined by this threshold without it having to traverse slits or beamsplitters.

quant-ph↗

arXiv2024

Two concurrent exponential decays in a vacuum capacitor-resistor circuit: effect of surface charge

The relaxation in a vacuum capacitor-resistor circuit is comprised of two exponential decays, one caused by surface charge and the other by the decay of energy stored between the capacitor plates. A simple phenomenological model of this relaxation is shown to be supported by measurements even though Maxwell's equations are difficult to apply in this case. Similar behavior is also observed for polypropylene capacitors, indicating that this surface charge effect is applicable to all capacitors and potentially other circuit components.

physics.app-ph↗

arXiv2024

The process of constructing new knowledge: an undergraduate laboratory exercise facilitated by a vacuum capacitor-resistor circuit

The process of constructing knowledge is typically taught to students by having them reproduce established results (e.g., homework problems). An alternative pedagogical strategy is to illustrate this process using an open problem, such as voltage decay in an RC circuit as described below. Analyzing data from this circuit in an undergraduate physics laboratory course reveals a discrepancy between the data and the exponential decay model found in textbooks. As students attempt to reconcile this discrepancy, the instructor can provide guidance in the process of validating data, modeling, and experimental design. This undergraduate laboratory exercise also provides an engaging transition from classroom learning to real world experience.

physics.ed-ph↗

arXiv2019

Three-particle quantum correlation interferometry

A three-body quantum correlation is calculated for two particles reflecting from a mirror. Correlated interference, a consequence of conservation of energy and momentum, occurs for states in which the order of reflection is indeterminate. The resulting quantum joint probability density function exhibits interference with diverse characteristics, depending on the coherence lengths of the substates. Marginal probability density functions can contain information about the quantum nature of all three bodies, even if only one particle is measured. Microscopic particles reflecting from a mesoscopic or macroscopic mirror are used to illustrate unique features of this three-body correlation interferometry. The microscopic momentum exchanged then generates mirror substates which interfere to produce quantum effects which do not vanish with increasing mirror mass, while the small displacement between these mirror states can yield negligible environmental decoherence times.

quant-ph↗

arXiv2015

Two-particle correlated interference in reflection: extending the quantum-classical boundary via a macroscopic quantum superposition insensitive to decoherence

Reflection of a microscopic particle from a mesoscopic/macroscopic `mirror' generates two-body correlated interference from the incident and reflected particle substates and their associated mirror substates. The microscopic momentum exchanged generates two mirror substates which interfere to produce fringes which do not vanish as the mirror mass increases. The small displacement between these mirror states can yield negligible environmental decoherence times. Mirror coherence lengths impose constraints on the extent of this interference, which are mitigated using interference of the two-body states associated with the particle reflecting from both of the two surfaces of a slab of matter in a manner analogous to the classical interference of a pulse of light reflecting from a `thin film'. This two-body correlated interference is modeled as a particle traversing a finite well with both the particle and well treated quantum mechanically. Such a treatment predicts the expected `thin-film' interference but only as a special case of a more general result. It is also shown that measurements on only the reflected particle (yielding a marginal probability density function) can act as a probe to reveal the quantum state of the macroscopic reflector. For equal masses, coherence of the particle substate is transferred to the mirror substate, a quantum manifestation of a familiar classical result.

quant-ph↗

arXiv2015

Two-particle asynchronous quantum correlation: wavefunction collapse acting as a beamsplitter

A two-body quantum correlation is calculated for a particle reflecting from a moving mirror. Correlated interference results when the incident and reflected particle substates and their associated mirror substates overlap. Using the Copenhagen interpretation of measurement, an asynchronous joint probability density (PDF), which is a function both of the different positions and different times at which the particle and mirror are measured, is derived assuming that no interaction occurs between each measurement. Measurement of the particle first, in the correlated interference region, results in a splitting of the mirror substate into ones which have and have not reflected the particle. An analog of the interference from the Doppler effect for only measurements of the particle (a marginal PDF), in this two-body system, is shown to be a consequence of the asynchronous measurement. The simplification obtained for a microscopic particle reflecting from a mesoscopic or macroscopic mirror is used to illustrate asynchronous correlation interferometry. In this case, the small displacement between these mirror states can yield negligible environmental decoherence times. In addition, interference of these mirror states does not vanish in the limit of large mirror mass due to the small momentum exchange in reflecting a microscopic particle.

quant-ph↗

arXiv2014

Quantum correlation between a particle and potential well or barrier

A two-body quantum correlation is calculated for a particle and an infinite potential well in which it is trapped or either a barrier or finite well over which it traverses. Correlated interference results when the incident and reflected particle substates and their associated well or barrier substates overlap. Measurement of the particle in this region causes a splitting of the well or barrier substate at subsequent times. The joint probability density, which is a function both of the different positions and different times at which the particle and well or barrier are measured, is derived assuming that no interaction occurs between the time each is measured.

quant-ph↗

arXiv2013

Using Inksurvey with Pen-enabled Mobile Devices for Real-time Formative Assessment I: Applications in Diverse Educational Enviroments

InkSurvey is free, web-based software designed to facilitate the collection of real-time formative assessment. Using this tool, the instructor can embed formative assessment in the instruction process by posing an open-format question. Students equipped with pen-enabled mobile devices (tablet PCs, iPads, Android devices including some smartphones) are then actively engaged in their learning as they use digital ink to draw, sketch, or graph their responses. When the instructor receives these responses instantaneously, it provides insights into student thinking and what the students do and do not know. Subsequent instruction can then repair and refine student understanding in a very timely manner. Although this pedagogical tool is appealing because of its broad theoretical foundations, the cost of pen-enabled mobile technology was until recently a significant barrier to widely implementing this teaching model. However, less expensive tablets, iPads, and Android devices are now filling the market (and student backpacks) and greatly lowering that barrier. To illustrate the wide applicability of this use of technology, we report a series of seven vignettes featuring instructors of diverse subjects (mathematics, food chemistry, physics, biology, and chemical engineering), with students using diverse pen-enabled mobile devices (tablet PCs, iPads, and Android 4.0 tablets), in diverse educational environments (K-12, community college, publicly-funded engineering university, private university, graduate school), in two countries (United States and Mexico). In a companion paper, each instructor also shares some data, insights, and/or conclusions from their experiences regarding the effectiveness of this tool.

physics.ed-ph↗

arXiv2013

Using Inksurvey with Pen-enabled Movile Devices for Real-time Formative Assessment II: Indications of Effectiveness in Diverse Educational Environments

InkSurvey is free, web-based software designed to facilitate the collection of real-time formative assessment. Using this tool, the instructor can embed formative assessment in the instruction process by posing an open-format question. Students equipped with pen-enabled mobile devices are then actively engaged in their learning as they use digital ink to draw, sketch, or graph their responses. When the instructor receives these responses instantaneously, it provides insights into student thinking and what the students do and do not know. Subsequent instruction can then repair and refine student understanding in a very timely manner. In a companion paper, we illustrate the wide applicability of this use of technology by reporting a series of seven vignettes featuring instructors of diverse subjects (physics, mathematics, chemical engineering, food science, and biology), with students using diverse pen-enabled mobile devices (tablet PCs, iPads, and Android 4.0 tablets/smartphones), in diverse educational environments (K-12, community college, publicly-funded engineering university, private university, and graduate school), in two countries (United States and Mexico). In this paper, each instructor shares some data, insights, and/or conclusions from their experiences that indicate the effectiveness of this pedagogical model in diverse educational environments.

physics.ed-ph↗

arXiv2013

Technology-Enabled Nurturing of Creativity and Innovation: A Specific Illustration from an Undergraduate Engineering Physics Course

There is general agreement that creativity and innovation are desirable traits in the toolbox of 21\textsuperscript{st} century engineers, as well as in the future workforce in general. However, there is a dearth of exemplars, pedagogical models, or best practices to be implemented in undergraduate engineering education to develop and nurture those talents. In this paper, we use a specific example of a classroom activity from a course designed to help bridge the transition from learning the fundamental principles of engineering physics in introductory courses to being able to creatively and innovatively apply them in more advanced settings, such as senior capstone projects and on-the-job challenges in the future workplace. Application of techniques for generating and evaluating ideas are described. To enhance the benefits of group creativity and facilitate real-time electronic brainstorming in the classroom, we use InkSurvey with pen-enabled mobile computing devices (iPads, tablet PCs, Android devices, etc.). Using this free, web-based software in this setting effectively mitigates many of the social issues that typically plague brainstorming in a group setting. The focus, instead, is on paying attention to the ideas of others while encouraging fluency, originality, and honing positive critical thinking skills. This emphasis is reflected as the group creates a metric to evaluate their potential solutions. A specific case from undergraduate and graduate level engineering physics courses is described to illustrate how the extensive work done in this arena in psychology, marketing, and business environments can be applied to STEM education. The classroom process is outlined and actual student results are presented to illustrate the method for other instructors who might be interested in employing similar activities in a non-threatening, low-stakes learning environment.

physics.ed-ph↗

arXiv2013

The Effect of Student Learning Styles on the Learning Gains Achieved When Interactive Simulations Are Coupled with Real-Time Formative Assessment via Pen-Enabled Mobile Technology

This paper describes results from a project in an undergraduate engineering physics course that coupled classroom use of interactive computer simulations with the collection of real-time formative assessment using pen-enabled mobile technology. Interactive simulations (free or textbook-based) are widely used across the undergraduate science and engineering curriculia to help actively engaged students increase their understanding of abstract concepts or phenomena which are not directly or easily observable. However, there are indications in the literature that we do not yet know the pedagogical best practices associated with their use to maximize learning. This project couples student use of interactive simulations with the gathering of real-time formative assessment via pen-enabled mobile technology (in this case, Tablet PCs). The research question addressed in this paper is: are learning gains achieved with this coupled model greater for certain types of learners in undergraduate STEM classrooms? To answer this, we correlate learning gains with various learning styles, as identified using the Index of Learning Styles (ILS) developed by Felder and Soloman. These insights will be useful for others who use interactive computer simulations in their instruction and other adopters of this pedagogical model; the insights may have broader implications about modification of instruction to address various learning styles.

physics.ed-ph↗

arXiv2013

Enhancing Curiosity Using Interactive Simulations Combined with Real-Time Formative Assessment Facilitated by Open-Format Questions on Tablet Computers

Students' curiosity often seems nearly nonexistent in a lecture setting; we discuss a variety of possible reasons for this, but it is the instructor who typically poses questions while only a few students, usually the better ones, respond. As we have developed and implemented the use of InkSurvey to collect real-time formative assessment, we have discovered that it can serve in an unanticipated role: to promote curiosity in engineering physics undergraduates. Curiosity often motivates creative, innovative people. To encourage such curiosity, we solicit questions submitted real-time via InkSurvey and pen-enabled mobile devices (Tablet PCs) in response to interactive simulations (applets) run either before or in class. This provides students with practice in asking questions, increases metacognition, and serves as a rich springboard from which to introduce content and/or address misconceptions. We describe the procedure for measuring curiosity and results from applying this method in a junior level electromagnetics engineering physics course. We conclude that students are indeed more curious than they appear in class, and students participate even without extrinsic motivation. This method of enhancing curiosity using interactive simulations coupled with real-time formative assessment in response to open-format questions could be implemented in a wide variety of science and engineering courses as well as elsewhere.

physics.ed-ph↗