Scholars@Duke
Stephen W. Teitsworth

Stephen W. Teitsworth

Associate Professor of Physics
Physics
stephen.teitsworth@duke.edu
Box 90305, Durham, NC 27708-0305
089 Physics Bldg, Durham, NC 27708

Selected Publications

Irreversible dynamics of a continuum driven by active matter

Journal Article Physical Review E · November 1, 2024 We study the fluctuational behavior of overdamped elastic filaments (e.g., strings or rods) driven by active matter which induces irreversibility. The statistics of discrete normal modes are translated into the continuum of the position representation whic ... Full text Cite

Stochastic line integrals and stream functions as metrics of irreversibility and heat transfer.

Journal Article Physical review. E · August 2022 Stochastic line integrals are presented as a useful metric for quantitatively characterizing irreversibility and detailed balance violation in noise-driven dynamical systems. A particular realization is the stochastic area, recently studied in coupled elec ... Full text Cite

Scaling properties of noise-induced switching in a bistable tunnel diode circuit

Journal Article European Physical Journal B · April 1, 2019 Abstract: Noise-induced switching between coexisting metastable states occurs in a wide range of far-from-equilibrium systems including micro-mechanical oscillators, epidemiological and climate change models, and nonlinear electronic transport in tunneling ... Full text Cite

Experimental metrics for detection of detailed balance violation.

Journal Article Physical review. E · February 2019 We report on the measurement of detailed balance violation in a coupled, noise-driven linear electronic circuit consisting of two nominally identical RC elements that are coupled via a variable capacitance. The state variables are the time-dependent voltag ... Full text Cite

The Geometry of most probable trajectories in noise-driven dynamical systems

Conference Springer Proceedings in Mathematics and Statistics · January 1, 2018 This paper presents a heuristic derivation of a geometric minimum action method that can be used to determine most-probable transition paths in noise-driven dynamical systems. Particular attention is focused on systems that violate detailed balance, and th ... Full text Cite

Fluctuation loops in noise-driven linear dynamical systems.

Journal Article Physical review. E · March 2017 Understanding the spatiotemporal structure of most probable fluctuation pathways to rarely occurring states is a central problem in the study of noise-driven, nonequilibrium dynamical systems. When the underlying system does not possess detailed balance, t ... Full text Cite

Steering most probable escape paths by varying relative noise intensities.

Journal Article Physical review letters · July 2014 We demonstrate the possibility to systematically steer the most probable escape paths (MPEPs) by adjusting relative noise intensities in dynamical systems that exhibit noise-induced escape from a metastable point via a saddle point. With the use of a geome ... Full text Cite

Noise-induced current switching in semiconductor superlattices: observation of nonexponential kinetics in a high-dimensional system.

Journal Article Physical review letters · July 2012 We report on measurements of first-passage-time distributions associated with current switching in weakly coupled GaAs/AlAs superlattices driven by shot noise, a system that is both far from equilibrium and high dimensional. Static current-voltage (I-V) ch ... Full text Cite

Noise-Induced Current Switching in Semiconductor Superlattices: Observation of Nonexponential Kinetics in a High-Dimensional System

Journal Article Physical Review Letters · 2012 We report on measurements of first-passage-time distributions associated with current switching in weakly coupled GaAs/AlAs superlattices driven by shot noise, a system that is both far from equilibrium and high dimensional. Static current-voltage (I-V) ch ... Cite

Symmetry-breaking transitions in networks of nonlinear circuit elements

Journal Article New Journal of Physics · November 1, 2010 We investigate a nonlinear circuit consisting of N tunnel diodes in series, which shows close similarities to a semiconductor superlattice or to a neural network. Each tunnel diode is modeled by a three-variable FitzHugh-Nagumo-like system. The tunnel diod ... Full text Cite

Nonlinear Wave Methods for Charge Transport

Journal Article Nonlinear Wave Methods for Charge Transport · September 20, 2010 The present book introduces and develops mathematical techniques for the treatment of nonlinear waves and singular perturbation methods at a level that is suitable for graduate students, researchers and faculty throughout the natural sciences and engineeri ... Full text Cite

Emergence of current branches in a series array of negative differential resistance circuit elements

Journal Article Journal of Applied Physics · August 15, 2010 We study a series array of nonlinear electrical circuit elements that possess negative differential resistance and find that heterogeneity in the element properties leads to the presence of multiple branches in current-voltage curves and a nonuniform distr ... Full text Open Access Cite

On the possibility of a shunt-stabilized superlattice terahertz emitter

Journal Article Applied Physics Letters · January 25, 2010 High field electronic transport through a strongly coupled superlattice (SL) with a shunting side layer is numerically studied using a drift-diffusion model that includes both vertical and lateral dynamics. The bias voltage corresponds to an average electr ... Full text Open Access Cite

On the possibility of a shunt-stabilized superlattice THz emitter

Journal Article Applied Physics Letters · 2010 High field electronic transport through a strongly-coupled superlattice (SL) with a shunting side layer is numerically studied using a novel drift-diffusion model. The bias voltage corresponds to an average electric field in the negative differential condu ... Cite

Nonlinear Wave Methods for Charge Transport

Journal Article Nonlinear Wave Methods for Charge Transport · 2010 Cite

Dynamics of electronic transport in a semiconductor superlattice with a shunting side layer

Journal Article Physical Review B - Condensed Matter and Materials Physics · June 19, 2009 We study a model describing electronic transport in a weakly coupled semiconductor superlattice with a shunting side layer. Key parameters include the lateral size of the superlattice, the connectivity between the quantum wells of the superlattice and the ... Full text Cite

Dynamics of electronic transport in a semiconductor superlattice with a shunting side layer

Journal Article Physical Review B · 2009 We study a model describing electronic transport in a weakly coupled semiconductor superlattice with a shunting side layer. Key parameters include the lateral size of the superlattice, the connectivity between the quantum wells of the superlattice and the ... Cite

Dependence of electric field domain relocation dynamics on contact conductivity in semiconductor superlattices

Journal Article Physical Review B - Condensed Matter and Materials Physics · December 3, 2007 Numerical simulation results are presented for a discrete drift-diffusion rate equation model that describes electronic transport due to sequential tunneling between adjacent quantum wells in weakly coupled semiconductor superlattices. We study the depende ... Full text Cite

Dependence of electric field domain relocation dynamics on contact conductivity in semiconductor superlattices

Journal Article Physical Review B · 2007 Numerical simulation results are presented for a discrete drift-diffusion rate equation model that describes electronic transport due to sequential tunneling between adjacent quantum wells in weakly coupled semiconductor superlattices. We study the depende ... Cite

Negative differential conductance and bistability in undoped GaAs/(Al,Ga)As quantum-cascade structures

Journal Article Journal of Applied Physics · August 11, 2006 We discuss the mechanisms for negative differential conductance (NDC) and bistable behavior observed in the current-density-electric-field (j-F) characteristics of undoped GaAs/Al 0.45Ga 0.55As quantum-cascade structures (QCSs). While the j-F characteristi ... Full text Cite

Negative differential conductance and bistability in undoped GaAs/AlGaAs quantum-cascade structures

Journal Article Journal of Applied Physics · July 2006 We discuss the mechanisms for negative differential conductance NDC and bistable behavior observed in the current-density–electric-field j-F characteristics of undoped GaAs/Al0.45Ga0.55As quantum-cascade structures QCSs . While the j-F characteristic ... Cite

Formation of electric-field domains in GaAs Alx Ga1-x As quantum cascade laser structures

Journal Article Physical Review B - Condensed Matter and Materials Physics · February 27, 2006 The current-voltage (I-V) characteristics of GaAs Alx Ga1-x As quantum cascade laser structures (QCLSs) are found to exhibit current plateaus with discontinuities for voltages below threshold. The number of current discontinuities is correlated with the nu ... Full text Cite

Formation of electric-field domains in GaAs/AlGaAs quantum cascade laser structures

Journal Article Physical Review B · January 2006 The current-voltage (I-V ) characteristics of GaAs/AlGaAs quantum-cascade laser structures (QCLSs) are found to exhibit current plateaus with discontinuities for voltages below threshold. The number of current discontinuities is correlated with the number ... Cite

Time distribution of the domain-boundary relocation in superlattices

Journal Article Physica B: Condensed Matter · March 1, 2002 Static domain formation in doped, weakly coupled semiconductor superlattices results in several current branches separated by discontinuities that exhibit hysteresis. The transition from one branch to its adjacent higher and lower one is studied by time-re ... Full text Cite

Relocation dynamics of domain boundaries in semiconductor superlattices

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2002 The formation of static electric-field domains in doped semiconductor superlattices appears in the current-voltage (formula presented) characteristics as multiple current branches separated by abrupt discontinuities. The switching dynamics of the charge-ac ... Full text Cite

Chaotic motion of space charge wave fronts in semiconductors under time-independent voltage bias.

Journal Article Physical review. E, Statistical, nonlinear, and soft matter physics · May 2001 A standard drift-diffusion model of space charge wave propagation in semiconductors has been studied numerically and analytically under dc voltage bias. For sufficiently long samples, appropriate contact resistivity, and applied voltage-such that the sampl ... Full text Cite

Statistics of the domain boundary relocation time in semiconductor superlattices

Journal Article Physical Review B - Rapid Communications · 2001 Cite

Statistics of the domain-boundary relocation time in semiconductor superlattices

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 2001 Static domain formation in doped semiconductor superlattices results in several current branches separated by abrupt discontinuities that exhibit hysteresis. The transition from one branch to its adjacent one is studied by time-resolved switching experimen ... Full text Cite

Chaotic motion of space charge wave fronts in semiconductors under time-independent voltage bias

Journal Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics · 2001 The chaos under dc voltage bias linked with multiple shedding of wave fronts were numerically simulated. Space charge wave dynamics was analyzed with a finite-dimensional model. Drift diffusion model of space charge wave propagation in semiconductors was s ... Cite

Photoluminescence of n-i-n GaAs/AlAs single quantum well structures under electric field bias

Journal Article Superlattices and Microstructures · January 1, 2000 GaAs/AlAs single quantum well structures designed with well thickness near the type-I/type-II crossover show distinctive photoluminescence peaks corresponding to both type-I and type-II recombinations. Photoluminescence measurements as a function of applie ... Full text Cite

Controllable bistabilities and bifurcations in a photoexcited GaAs/AlAs superlattice

Journal Article Applied Physics Letters · June 21, 1999 Self-sustained photocurrent oscillations and bifurcation process have been demonstrated on an undoped photoexcited GaAs/AlAs superlattice. The effects of carrier density, varied by changing the laser intensity, on the transition between static and oscillat ... Full text Cite

Influence of higher harmonics on Poincaré maps derived from current self-oscillations in a semiconductor superlattice

Journal Article Physical Review B - Condensed Matter and Materials Physics · January 1, 1998 The effect of higher harmonics on the shape of Poincaré maps (first return maps) derived from current self-oscillations has been investigated in a semiconductor superlattice system driven by a dc + ac voltage bias. In addition to the intrinsic fundamental ... Full text Cite

Dependence of current-voltage characteristics on Al mole fraction in GaAs/AlxGa1-xAs asymmetric double barrier structures

Journal Article Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures · May 1, 1997 The effect of barrier Al mole fraction, 0.2≤x≤0.8. on tunneling currents has been studied for a set of asymmetric GaAs/AlxGa1-xAs double barrier structures. The barrier widths of each sample were scaled so that barrier transmission coefficients for differe ... Cite

Solitary-wave conduction in p-type Ge under time-dependent voltage bias.

Journal Article Physical review. B, Condensed matter · January 1996 Full text Cite

Phonon scattering in novel superlattice-asymmetric double barrier resonant tunneling structure

Journal Article Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures · 1996 The scattering effects (specifically LO-phonon scattering) in a 45 Å AlAs/80 Å GaAs/33 A AlAs asymmetric double barrier resonant tunneling (ADBRT) structure with a short period GaAS/Al0.3Ga0.7As superlattice incorporated on one side of the double barrier h ... Cite

Interface phonons in spherical GaAs/AlxGa1-xAs quantum dots.

Journal Article Physical review. B, Condensed matter · July 1995 Full text Cite

Selection rule for localized phonon emission in GaAs/AlAs double-barrier structures

Journal Article Journal of Applied Physics · January 1, 1995 Phonon-assisted tunneling (PAT) has been studied in detail for two similar GaAs/AlAs double-barrier structures. Calculations of the PAT current - including effects of optical-phonon localization - are in good agreement with experimental data, and the emiss ... Full text Cite

Hopf bifurcations and hysteresis in resonant tunneling diode circuits

Journal Article Journal of Applied Physics · December 1, 1994 Conditions for Hopf bifurcations and associated current oscillations are presented for a standard model of a resonant tunneling diode circuit. We derive a simple analytic formula for the Hopf bifurcation type (subcritical or supercritical) and discuss how ... Full text Cite

Onset of current oscillations in extrinsic semiconductors under DC voltage bias

Journal Article Semiconductor Science and Technology · December 1, 1994 We present a model which describes the onset of current instabilities and space-charge domains in extrinsic semiconductors (especially p-Ge) under DC voltage bias. Just above the onset voltage for current instability we have found numerically small-amplitu ... Full text Cite

Magnetotunnelling measurements of localized optical phonons in GaAs/AlAs double-barrier structures

Journal Article Semiconductor Science and Technology · December 1, 1994 We have measured current-voltage characteristics at liquid-helium temperature and for magnetic fields up to 7T(parallel to the current flow) for three similar asymmetric GaAs/AlAs double-barrier structures, all of which possess large phonon-assisted tunnel ... Full text Cite

Phonon-assisted tunneling from a two-dimensional emitter state.

Journal Article Physical review. B, Condensed matter · September 1994 Full text Cite

Solitary-wave dynamics in extrinsic semiconductors under dc voltage bias.

Journal Article Physical review. B, Condensed matter · October 1993 Full text Cite

Bottleneck effects due to confined phonons in quantum dots

Journal Article Superlattices and Microstructures · January 1, 1993 A generalization of the three-dimensional Fröhlich hamiltonian for a polar semiconductor is presented which describes the interaction between charge carriers of a zero-dimensional electron gas and longitudinal optical (LO) phonon modes confined in three sp ... Full text Cite

Effects of interface phonon scattering in multiheterointerface structures

Journal Article Journal of Applied Physics · December 1, 1992 In this paper, the commonly used but idealistic formulation of quantized optical-phonon modes for a heterostructure system with only two heterojunctions (i.e., single quantum-well structures) is extended to the more realistic case of multiheterointerface s ... Full text Cite

Theory of localized phonon modes and their effects on electron tunneling in double-barrier structures

Journal Article Journal of Applied Physics · December 1, 1992 The role of localized phonon modes in phonon-assisted tunneling in GaAs/AlAs double-barrier resonant tunneling structures is considered for a range of temperatures and magnetic fields. Phonon modes are calculated using a dielectric continuum model and elec ... Full text Cite

Effects of localized phonon modes on magnetotunneling spectra in double-barrier structures.

Journal Article Physical review. B, Condensed matter · December 1991 Full text Cite

Phonon-assisted tunneling due to localized modes in double-barrier structures.

Journal Article Physical review. B, Condensed matter · October 1991 Full text Cite

Theory of periodic and solitary space charge waves in extrinsic semiconductors

Journal Article Physica D: Nonlinear Phenomena · January 1, 1991 We present a theory of the existence and stability of traveling periodic and solitary space charge wave solutions to a standard rate equation model of electrical conduction in extrinsic semiconductors which includes effects of field-dependent impurity impa ... Full text Cite

The physics of space charge instabilities and temporal chaos in extrinsic photoconductors

Journal Article Applied Physics A Solids and Surfaces · February 1, 1989 This paper reviews experimental and theoretical work carried out on space charge instabilities and temporal chaotic behavior in cooled extrinsic p-type Germanium photoconductors. Measured dc current-voltage (I-V) characteristics of these devices are strong ... Full text Cite

Chaotic dynamics in Ge photoconductors

Journal Article Nuclear Physics B (Proceedings Supplements) · January 1, 1987 Experimental tests are presented of universal predictions of the circle map for the response of driven nonlinear oscillators, using a spatio-temporal instability associated with impurity impact ionization in liquid He cooled p-type Ge. Both the measured po ... Full text Cite

Nonlinear dynamics and chaos in extrinsic photoconductors

Journal Article Physica D: Nonlinear Phenomena · January 1, 1986 We present an experimental and theoretical analysis of the nonlinear response of cooled extrinsic Ge photoconductors of the type used to detect far-infrared radiation. State of the art p-type Ge devices with nearly ideal noise performance in the absence of ... Full text Cite

Chaotic dynamics in ge photoconductors

Journal Article Physica Scripta · January 1, 1986 Two sets of experimental results are given to demonstrate how modern nonlinear dynamics can be used to understand the dynamics of extrinsic Ge photoconductors. In the first, we show how complex and apparently random chaotic broadband noise is physically pr ... Full text Cite

Nonlinear current-voltage characteristics and spontaneous current oscillations in p-Ge

Journal Article Physica D: Nonlinear Phenomena · January 1, 1986 We report an experimental measurement of nonlinear dc current-voltage (I-V) characteristics in p-type Ge extrinsic photoconductors at liquid He temperatures which exhibit a region of voltage-controlled negative differential resistance (NDR) above the thres ... Full text Cite

Chaotic dynamics in a simple model of extrinsic photoconductors

Journal Article Physica Scripta · January 1, 1986 We have studied the nonlinear dynamical properties of a simple periodicallydriven rate equation model describing electrical conduction in extrinsic photoconductors. Extensive numerical simulations analysed using phase portraits, Poincart sections, approxim ... Full text Cite

Nonlinear transient response of extrinsic Ge far-infrared photoconductors

Journal Article Journal of Applied Physics · December 1, 1985 Physical mechanisms responsible for nonlinear phenomena and anomalous transient response of cooled extrinsic far-infrared photoconductors are discussed. A simple model describing carrier generation, trapping, and impact ionization is presented, which descr ... Full text Cite

Chaos and broadband noise in extrinsic photoconductors

Journal Article Physical Review Letters · January 1, 1984 A simple model is studied describing low-temperature free-carrier dynamics in extrinsic photoconductors due to capture by impurity atoms and impact ionization. Numerical results are presented which exhibit period doubling, chaotic behavior, and elevated ef ... Full text Cite

Nonlinear oscillations and chaos in electrical breakdown in Ge

Journal Article Physical Review Letters · January 1, 1983 Self-generated nonlinear oscillations and chaos are found in the conductance of liquid-He-cooled far-infrared photoconductors made from ultrapure Ge. Complex behavior includes a period-doubling cascade to chaotic oscillation with increasing applied electri ... Full text Cite