Now showing items 1-17 of 17

• #### Causality, 'superluminality', and reshaping in undersized waveguides ﻿

(2012-12-31)
We analyse the reshaping mechanism leading to apparently 'superluminal' advancement of a pulse traversing an undersized section of a waveguide. For frequencies below the first inelastic threshold (cut off one), there are ...
• #### Classification of resonance Regge trajectories and a modified Mulholland formula ﻿

(2011-12-31)
We employ a simple potential model to analyze the effects which a Regge trajectory, correlating with a bound or a metastable state at zero angular momentum, has on an integral cross section. A straightforward modification ...
• #### Complex angular momentum theory of state-to-state integral cross sections: Resonance effects in the $F + HD \to HF(v' = 3) + D$ reaction ﻿

(2015-12-31)
State-to-state reactive integral cross sections (ICSs) are often affected by quantum mechanical resonances, especially near a reactive threshold. An ICS is usually obtained by summing partial waves at a given value of ...
• #### Computer software for understanding resonances and resonance-related phenomena in chemical reactions ﻿

(2014-12-31)
In numerical modelling of chemical reactions one calculates the scattering matrix for the required values of energy and angular momentum. Having done so, one still faces the non-trivial task of extracting detailed information ...
• #### An even simpler understanding of quantum weak values ﻿

(2018-01)
We explain the properties and clarify the meaning of quantum weak values using only the basic notions of elementary quantum mechanics.
• #### Extracting S-matrix poles for resonances from numerical scattering data: Type-II Padé reconstruction ﻿

(2011-12-31)
We present a FORTRAN 77 code for evaluation of resonance pole positions and residues of a numerical scattering matrix element in the complex energy (CE) as well as in the complex angular momentum (CAM) planes. Analytical ...
• #### Hartman effect and weak measurements that are not really weak ﻿

(2011-12-31)
We show that in wave packet tunneling, localization of the transmitted particle amounts to a quantum measurement of the delay it experiences in the barrier. With no external degree of freedom involved, the envelope of the ...
• #### Impact of competitive processes on controlled radical polymerization ﻿

(2014-12-31)
The kinetics of radical polymerization have been systematically studied for nearly a century and in general are well understood. However, in light of recent developments in controlled radical polymerization many kinetic ...
• #### Interference mechanism of seemingly superluminal tunneling ﻿

(2013-12-31)
Apparently "superluminal" transmission, e.g., in quantum tunneling and its variants, occurs via a subtle interference mechanism which allows reconstruction of the entire spatial shape of a wave packet from its front tail. ...
• #### No Time at the End of the Tunnel ﻿

(2018-08-21)
Modern atto-second experiments seek to provide an insight into a long standing question: “how much time does a tunnelling particle spend in the barrier?” Traditionally, quantum theory relates this duration to the delay ...
• #### Non-Markovian models of the growth of a polymer chain ﻿

(2015-12-31)
Using simple exactly solvable models, we show that event-dependent time delays may lead to significant non-Poisson effects in the statistics of polymer chain growth. The results are confirmed by stochastic simulation of ...
• #### Numerical Regge pole analysis of resonance structures in elastic, inelastic and reactive state-to-state integral cross sections ﻿

(2014-12-31)
We present a detailed description of a FORTRAN code for evaluation of the resonance contribution a Regge trajectory makes to the integral state-to-state cross section (ICS) within a specified range of energies. The ...
• #### An optimal scaling to computationally tractable dimensionless models: Study of latex particles morphology formation ﻿

(2020-02)
In modelling of chemical, physical or biological systems it may occur that the coefficients, multiplying various terms in the equation of interest, differ greatly in magnitude, if a particular system of units is used. Such ...
• #### Reexamination of continuous fuzzy measurement on two-level systems ﻿

(2017-04-10)
Imposing restrictions on the Feynman paths of the monitored system has in the past been proposed as a universal model-free approach to continuous quantum measurements. Here we revisit this proposition and demonstrate that ...
• #### Relative frequencies of constrained events in stochastic processes: An analytical approach ﻿

(2015-12-31)
The stochastic simulation algorithm (SSA) and the corresponding Monte Carlo (MC) method are among the most common approaches for studying stochastic processes. They relies on knowledge of interevent probability density ...
• #### 'Superluminal paradox' in wave packet propagation and its quantum mechanical resolution ﻿

(2013-12-31)
We analyse in detail the reshaping mechanism leading to apparently 'superluminal' advancement of a wave packet traversing a classically forbidden region. In the coordinate representation, a barrier is shown to act as an ...
• #### Tunnelling times, Larmor clock, and the elephant in the room ﻿

(2021-05-11)
A controversy surrounding the “tunnelling time problem” stems from the seeming inability of quantum mechanics to provide, in the usual way, a definition of the duration a particle is supposed to spend in a given region of ...