Reuven Ianconescu - Academia.edu (original) (raw)
Papers by Reuven Ianconescu
Physical Review Letters, 2021
We present a comprehensive relativistic quantum-mechanical theory for interaction of a free elect... more We present a comprehensive relativistic quantum-mechanical theory for interaction of a free electron with a bound electron in a model, where the free electron is represented as a finite-size quantum electron wave packet (QEW) and the bound electron is modeled by a quantum two-level system (TLS). The analysis reveals the wave-particle duality nature of the QEW, delineating the point-particle-like and wavelike interaction regimes and manifesting the physical reality of the wave function dimensions when interacting with matter. This QEW size dependence may be used for interrogation and coherent control of superposition states in a TLS and for enhancement of cathodoluminescence and electron energy-loss spectroscopy in electron microscopy.
The Journal of Chemical Physics, 2019
The recently improved Pollak, Grabert, and Hänggi (PGH) turnover theory for activated surface dif... more The recently improved Pollak, Grabert, and Hänggi (PGH) turnover theory for activated surface diffusion, including finite barrier effects, is extended and studied in the quantum domain. Analytic expressions are presented for the diffusion coefficient, escape rate, hopping distribution, and mean squared path length of particles initially trapped in one of the wells of a periodic potential, moving under the influence of a frictional and Gaussian random force. Tunneling is included by assuming incoherent quantum hopping at temperatures which are above the crossover temperature between deep tunneling and thermal activation. In the improved version of PGH theory as applied to activated surface diffusion, the potential governing the motion of the unstable mode remains periodic but with a scaled mass which increases with the friction strength. Application of the theory to a periodic cosine potential demonstrates that in the weak damping regime quantum diffusion is slower than classical dif...
Free-Electron Bound-Electron Resonant Interaction (FEBERI) is the resonant inelastic interaction ... more Free-Electron Bound-Electron Resonant Interaction (FEBERI) is the resonant inelastic interaction of periodically density-bunched free electrons with a quantum two level system. We present a comprehensive relativistic quantum mechanical theory for this interaction in a model in which the electrons are represented as quantum electron wavepackets (QEW). The analysis reveals the wave-particle duality nature of the QEW, delineating the point-particle-like and wave-like interaction regimes, and manifesting the physical reality of the wavefunction dimensions and its density modulation characteristics in interaction with matter. The analysis comprehends the case of laser-beam-modulated multiple QEWs that are modulation-phase correlated. Based on the Born interpretation of the electron wavefunction we predict quantum transitions enhancement proportional to the number of electrons squared, analogous to superradiance.
New Journal of Physics
In this work, we propose a composite pulses scheme by modulating phases to achieve high fidelity ... more In this work, we propose a composite pulses scheme by modulating phases to achieve high fidelity population transfer in three-level systems. To circumvent the obstacle that not enough variables are exploited to eliminate the systematic errors in the transition probability, we put forward a cost function to find the optimal value. The cost function is independently constructed either in ensuring an accurate population of the target state, or in suppressing the population of the leakage state, or both of them. The results demonstrate that population transfer is implemented with high fidelity even when existing the deviations in the coupling coefficients. Furthermore, our composite pulses scheme can be extensible to arbitrarily long pulse sequences. As an example, we employ the composite pulses sequence for achieving the three-atom singlet state in an atom-cavity system with ultrahigh fidelity. The final singlet state shows robustness against deviations and is not seriously affected by...
2016 IEEE International Conference on the Science of Electrical Engineering (ICSEE), 2016
A pacemaker is a small medical device that uses electrical impulses to regulate the heart beating... more A pacemaker is a small medical device that uses electrical impulses to regulate the heart beating. There are pacemakers with additional capabilities, like gathering information from the human body in order to transmit them to an external receiver. In this paper we present a communication link design between a pacemaker inside the human body and an external receiver. The pacemaker is equipped with an inverted F antenna, transmitting to the external receiver, which is connected through a microstrip patch antenna.
The analysis of the EM radiation from a single charge shows that the radiated power depends on th... more The analysis of the EM radiation from a single charge shows that the radiated power depends on the retarded acceleration of the charge. Therefore for consistency, an accelerated charge, free from the influence of external forces, should gradually lose its acceleration, until its total energy is radiated. Calculations show that the self force of a charge, which compensates for its radiation, is proportional to the derivative of the acceleration. However, when using this self force in the equation of motion of the charge, one gets a diverging solution, for which the acceleration runs away to infinity. This means that there is an inconsistency in the solution of the single charge problem. However, in the con-
Physical Review A, 2021
The oscillating-barrier model was used by Büttiker and Landauer to determine a "traversal time fo... more The oscillating-barrier model was used by Büttiker and Landauer to determine a "traversal time for tunneling." The model sets a timescale but is not the physically measured flight time of a wave packet scattered on the oscillating-barrier potential. In this paper we show that the flight time in the limit of a narrow-in-momentum wave packet is given by the reflected phase time associated with the various branches of the scattered particle. This is but another example which establishes that tunneling flight times are a reflection of the Wigner phase times. As such, the oscillating-barrier model does not add any new information about tunneling flight times which has not been elucidated previously using static barrier models.
2017 IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems (COMCAS), 2017
In a previous work we developed a model for radiation losses in two conductors TEM transmission l... more In a previous work we developed a model for radiation losses in two conductors TEM transmission lines in free space. In this work we develop some fundamentals to generalize the above model for two conductors in dielectric insulation transmission lines.
2019 IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems (COMCAS), 2019
The interpretation of the S parameters concerning power balance is often misunderstood. This work... more The interpretation of the S parameters concerning power balance is often misunderstood. This work analyzes the power balance in systems described by S parameters and defines more accurate criteria for examining this property.
There are three kind of losses in transmission lines: ohmic, dielectric and radiation losses. Whi... more There are three kind of losses in transmission lines: ohmic, dielectric and radiation losses. While the first two are local phenomena which are easy to model, the radiation losses lack a simple model. We show that the losses model for the ohmic and dielectric allows a simple calculation of losses only in the case of matched line, and the calculation complicates in the case of unmatched line. The aim of this work is to find some possible radiation model for matched transmission lines.
Optics Letters
We propose a scheme to control the evolution of a twolevel quantum system in the strong coupling ... more We propose a scheme to control the evolution of a twolevel quantum system in the strong coupling regime based on the idea of reverse-engineering. A coherent control field is designed to drive both closed and open two-level quantum systems along user predefined evolution trajectory without utilizing the rotatingwave approximation (RWA). As concrete examples, we show that complete population inversion, an equally weighted coherent superposition, and even oscillationlike dynamics can be achieved. As there are no limitations on the coupling strength between the control field and matter, the scheme is attractive for applications such as accelerating desired system dynamics and fast quantum information processing.
Correlated electron beam microbunching and shot-noise characterization with near-and far-field optical transition radiation, 2019
In this work we demonstrate how to analyze the dynamics of the correlated longitudinal current no... more In this work we demonstrate how to analyze the dynamics of the correlated longitudinal current noise above and below the Poissonian shot-noise level in an e-beam, by calculating the emitted transition radiation (OTR) using a complex vector field formulation which is exact in the near and far fields. We simulate a non-zero emittance electron beam, uncorrelated in the transverse cross section, but with different types of longitudinal correlations, resulting in coherent optical transition radiation. We show how this method is applied on the opposite case (suppression), by tracking simulated beam particles that correlate due to quarter-plasma oscillation during drift, and show how the OTR tracks the dynamics of the electron beam noise level.
IET Microwaves, Antennas & Propagation
This work derives exact expressions for the radiation from two conductors non isolated TEM transm... more This work derives exact expressions for the radiation from two conductors non isolated TEM transmission lines of any cross section in free space. We cover the cases of infinite, semi-infinite and finite transmission lines and show that while an infinite transmission line does not radiate, there is a smooth transition between the radiation from a finite to a semi-infinite transmission line. Our analysis is in the frequency domain and we consider transmission lines carrying any combination of forward and backward waves. The analytic results are validated by successful comparison with ANSYS commercial software simulation results, and successful comparisons with other published results.
New Journal of Physics, 2016
The collective motion of groups of animals emerges from the net effect of the interactions betwee... more The collective motion of groups of animals emerges from the net effect of the interactions between individual members of the group. In many cases, such as birds, fish, or ungulates, these interactions are mediated by sensory stimuli that predominantly arise from nearby neighbors. But not all stimuli in animal groups are short range. Here, we consider mating swarms of midges, which are thought to interact primarily via long-range acoustic stimuli. We exploit the similarity in form between the decay of acoustic and gravitational sources to build a model for swarm behavior. By accounting for the adaptive nature of the midges' acoustic sensing, we show that our 'adaptive gravity' model makes mean-field predictions that agree well with experimental observations of laboratory swarms. Our results highlight the role of sensory mechanisms and interaction range in collective animal behavior. Additionally, the adaptive interactions that we present here open a new class of equations of motion, which may appear in other biological contexts.
2016 46th European Microwave Conference (EuMC), 2016
There are three kind of losses in transmission lines: ohmic, dielectric and radiation losses. Whi... more There are three kind of losses in transmission lines: ohmic, dielectric and radiation losses. While the first two are local phenomena which are easy to model, the radiation losses lack a simple model. This is because the radiation is a global process, determined by the constructive interference in the far field of the individual contributions, rather than the local behavior of the current. The aim of the current work is to analyze the radiation process from transmission lines, aiming to find some possible radiation model.
Modern Applied Science, 2013
Guided TEM waves have been extensively investigated between 2 conductors. The multiconductor case... more Guided TEM waves have been extensively investigated between 2 conductors. The multiconductor case, in spite of some important publications in this direction, did not get into the mainstream of the electromagnetic education, and therefore deserves some more attention. The simple case of lossless multiconductor TEM waves in homogeneous media is a good approximation for many practical cases and is easily derivable by usage of potentials only. In this work we derive the formalism for lossless multiconductor TEM waves in homogeneous media, and show several examples for the usage of this formalism.
2015 IEEE International Conference on Microwaves, Communications, Antennas and Electronic Systems (COMCAS), 2015
IET Microwaves, Antennas & Propagation, 2015
2014 IEEE 28th Convention of Electrical & Electronics Engineers in Israel (IEEEI), 2014
Physical Review Letters, 2021
We present a comprehensive relativistic quantum-mechanical theory for interaction of a free elect... more We present a comprehensive relativistic quantum-mechanical theory for interaction of a free electron with a bound electron in a model, where the free electron is represented as a finite-size quantum electron wave packet (QEW) and the bound electron is modeled by a quantum two-level system (TLS). The analysis reveals the wave-particle duality nature of the QEW, delineating the point-particle-like and wavelike interaction regimes and manifesting the physical reality of the wave function dimensions when interacting with matter. This QEW size dependence may be used for interrogation and coherent control of superposition states in a TLS and for enhancement of cathodoluminescence and electron energy-loss spectroscopy in electron microscopy.
The Journal of Chemical Physics, 2019
The recently improved Pollak, Grabert, and Hänggi (PGH) turnover theory for activated surface dif... more The recently improved Pollak, Grabert, and Hänggi (PGH) turnover theory for activated surface diffusion, including finite barrier effects, is extended and studied in the quantum domain. Analytic expressions are presented for the diffusion coefficient, escape rate, hopping distribution, and mean squared path length of particles initially trapped in one of the wells of a periodic potential, moving under the influence of a frictional and Gaussian random force. Tunneling is included by assuming incoherent quantum hopping at temperatures which are above the crossover temperature between deep tunneling and thermal activation. In the improved version of PGH theory as applied to activated surface diffusion, the potential governing the motion of the unstable mode remains periodic but with a scaled mass which increases with the friction strength. Application of the theory to a periodic cosine potential demonstrates that in the weak damping regime quantum diffusion is slower than classical dif...
Free-Electron Bound-Electron Resonant Interaction (FEBERI) is the resonant inelastic interaction ... more Free-Electron Bound-Electron Resonant Interaction (FEBERI) is the resonant inelastic interaction of periodically density-bunched free electrons with a quantum two level system. We present a comprehensive relativistic quantum mechanical theory for this interaction in a model in which the electrons are represented as quantum electron wavepackets (QEW). The analysis reveals the wave-particle duality nature of the QEW, delineating the point-particle-like and wave-like interaction regimes, and manifesting the physical reality of the wavefunction dimensions and its density modulation characteristics in interaction with matter. The analysis comprehends the case of laser-beam-modulated multiple QEWs that are modulation-phase correlated. Based on the Born interpretation of the electron wavefunction we predict quantum transitions enhancement proportional to the number of electrons squared, analogous to superradiance.
New Journal of Physics
In this work, we propose a composite pulses scheme by modulating phases to achieve high fidelity ... more In this work, we propose a composite pulses scheme by modulating phases to achieve high fidelity population transfer in three-level systems. To circumvent the obstacle that not enough variables are exploited to eliminate the systematic errors in the transition probability, we put forward a cost function to find the optimal value. The cost function is independently constructed either in ensuring an accurate population of the target state, or in suppressing the population of the leakage state, or both of them. The results demonstrate that population transfer is implemented with high fidelity even when existing the deviations in the coupling coefficients. Furthermore, our composite pulses scheme can be extensible to arbitrarily long pulse sequences. As an example, we employ the composite pulses sequence for achieving the three-atom singlet state in an atom-cavity system with ultrahigh fidelity. The final singlet state shows robustness against deviations and is not seriously affected by...
2016 IEEE International Conference on the Science of Electrical Engineering (ICSEE), 2016
A pacemaker is a small medical device that uses electrical impulses to regulate the heart beating... more A pacemaker is a small medical device that uses electrical impulses to regulate the heart beating. There are pacemakers with additional capabilities, like gathering information from the human body in order to transmit them to an external receiver. In this paper we present a communication link design between a pacemaker inside the human body and an external receiver. The pacemaker is equipped with an inverted F antenna, transmitting to the external receiver, which is connected through a microstrip patch antenna.
The analysis of the EM radiation from a single charge shows that the radiated power depends on th... more The analysis of the EM radiation from a single charge shows that the radiated power depends on the retarded acceleration of the charge. Therefore for consistency, an accelerated charge, free from the influence of external forces, should gradually lose its acceleration, until its total energy is radiated. Calculations show that the self force of a charge, which compensates for its radiation, is proportional to the derivative of the acceleration. However, when using this self force in the equation of motion of the charge, one gets a diverging solution, for which the acceleration runs away to infinity. This means that there is an inconsistency in the solution of the single charge problem. However, in the con-
Physical Review A, 2021
The oscillating-barrier model was used by Büttiker and Landauer to determine a "traversal time fo... more The oscillating-barrier model was used by Büttiker and Landauer to determine a "traversal time for tunneling." The model sets a timescale but is not the physically measured flight time of a wave packet scattered on the oscillating-barrier potential. In this paper we show that the flight time in the limit of a narrow-in-momentum wave packet is given by the reflected phase time associated with the various branches of the scattered particle. This is but another example which establishes that tunneling flight times are a reflection of the Wigner phase times. As such, the oscillating-barrier model does not add any new information about tunneling flight times which has not been elucidated previously using static barrier models.
2017 IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems (COMCAS), 2017
In a previous work we developed a model for radiation losses in two conductors TEM transmission l... more In a previous work we developed a model for radiation losses in two conductors TEM transmission lines in free space. In this work we develop some fundamentals to generalize the above model for two conductors in dielectric insulation transmission lines.
2019 IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems (COMCAS), 2019
The interpretation of the S parameters concerning power balance is often misunderstood. This work... more The interpretation of the S parameters concerning power balance is often misunderstood. This work analyzes the power balance in systems described by S parameters and defines more accurate criteria for examining this property.
There are three kind of losses in transmission lines: ohmic, dielectric and radiation losses. Whi... more There are three kind of losses in transmission lines: ohmic, dielectric and radiation losses. While the first two are local phenomena which are easy to model, the radiation losses lack a simple model. We show that the losses model for the ohmic and dielectric allows a simple calculation of losses only in the case of matched line, and the calculation complicates in the case of unmatched line. The aim of this work is to find some possible radiation model for matched transmission lines.
Optics Letters
We propose a scheme to control the evolution of a twolevel quantum system in the strong coupling ... more We propose a scheme to control the evolution of a twolevel quantum system in the strong coupling regime based on the idea of reverse-engineering. A coherent control field is designed to drive both closed and open two-level quantum systems along user predefined evolution trajectory without utilizing the rotatingwave approximation (RWA). As concrete examples, we show that complete population inversion, an equally weighted coherent superposition, and even oscillationlike dynamics can be achieved. As there are no limitations on the coupling strength between the control field and matter, the scheme is attractive for applications such as accelerating desired system dynamics and fast quantum information processing.
Correlated electron beam microbunching and shot-noise characterization with near-and far-field optical transition radiation, 2019
In this work we demonstrate how to analyze the dynamics of the correlated longitudinal current no... more In this work we demonstrate how to analyze the dynamics of the correlated longitudinal current noise above and below the Poissonian shot-noise level in an e-beam, by calculating the emitted transition radiation (OTR) using a complex vector field formulation which is exact in the near and far fields. We simulate a non-zero emittance electron beam, uncorrelated in the transverse cross section, but with different types of longitudinal correlations, resulting in coherent optical transition radiation. We show how this method is applied on the opposite case (suppression), by tracking simulated beam particles that correlate due to quarter-plasma oscillation during drift, and show how the OTR tracks the dynamics of the electron beam noise level.
IET Microwaves, Antennas & Propagation
This work derives exact expressions for the radiation from two conductors non isolated TEM transm... more This work derives exact expressions for the radiation from two conductors non isolated TEM transmission lines of any cross section in free space. We cover the cases of infinite, semi-infinite and finite transmission lines and show that while an infinite transmission line does not radiate, there is a smooth transition between the radiation from a finite to a semi-infinite transmission line. Our analysis is in the frequency domain and we consider transmission lines carrying any combination of forward and backward waves. The analytic results are validated by successful comparison with ANSYS commercial software simulation results, and successful comparisons with other published results.
New Journal of Physics, 2016
The collective motion of groups of animals emerges from the net effect of the interactions betwee... more The collective motion of groups of animals emerges from the net effect of the interactions between individual members of the group. In many cases, such as birds, fish, or ungulates, these interactions are mediated by sensory stimuli that predominantly arise from nearby neighbors. But not all stimuli in animal groups are short range. Here, we consider mating swarms of midges, which are thought to interact primarily via long-range acoustic stimuli. We exploit the similarity in form between the decay of acoustic and gravitational sources to build a model for swarm behavior. By accounting for the adaptive nature of the midges' acoustic sensing, we show that our 'adaptive gravity' model makes mean-field predictions that agree well with experimental observations of laboratory swarms. Our results highlight the role of sensory mechanisms and interaction range in collective animal behavior. Additionally, the adaptive interactions that we present here open a new class of equations of motion, which may appear in other biological contexts.
2016 46th European Microwave Conference (EuMC), 2016
There are three kind of losses in transmission lines: ohmic, dielectric and radiation losses. Whi... more There are three kind of losses in transmission lines: ohmic, dielectric and radiation losses. While the first two are local phenomena which are easy to model, the radiation losses lack a simple model. This is because the radiation is a global process, determined by the constructive interference in the far field of the individual contributions, rather than the local behavior of the current. The aim of the current work is to analyze the radiation process from transmission lines, aiming to find some possible radiation model.
Modern Applied Science, 2013
Guided TEM waves have been extensively investigated between 2 conductors. The multiconductor case... more Guided TEM waves have been extensively investigated between 2 conductors. The multiconductor case, in spite of some important publications in this direction, did not get into the mainstream of the electromagnetic education, and therefore deserves some more attention. The simple case of lossless multiconductor TEM waves in homogeneous media is a good approximation for many practical cases and is easily derivable by usage of potentials only. In this work we derive the formalism for lossless multiconductor TEM waves in homogeneous media, and show several examples for the usage of this formalism.
2015 IEEE International Conference on Microwaves, Communications, Antennas and Electronic Systems (COMCAS), 2015
IET Microwaves, Antennas & Propagation, 2015
2014 IEEE 28th Convention of Electrical & Electronics Engineers in Israel (IEEEI), 2014