Department of Physics

Phases of dipolar bosons in a bilayer geometry

Cinti, Fabio; Wang, Daw-Wei; Boninsegni, Massimo (American Physical Society, 2017)

We study, by first-principles computer simulations, the low-temperature phase diagram of bosonic dipolar gases in a bilayer geometry as a function of the two control parameters, i.e., the in-plane density and the ...

Towards the improvement of spin-isospin properties in nuclear energy density functionals

Roca-Maza, X.; Colo, G.; Liang, H. Z.; Meng, J.; Ring, P.; Sagawa, H.; Zhao, P. W. (IOP Publishing, 2016)

We address the problem of improving existing nuclear Energy Density Functionals (EDFs) in the spin-isospin channel. For that, we propose two different ways. The first one is to carefully take into account in the fitting ...

Towards atomic physics using spatially structured light

Webster, Jason (Stellenbosch : Stellenbosch University, 2018-12)

ENGLISH ABSTRACT : Structured light has seen many applications in the fields of telecommunications, optical microscopy, and quantum information processing, however, few works exist that explore the interactions of ...

Mechanical properties of cells and modelling of structural instabilities in tissues

Azote, Somiealo (Stellenbosch : Stellenbosch University, 2018-12)

ENGLISH ABSTRACT : Cells have inherent mechanical properties that can be modelled physically. Statistical physics approaches permit the understanding of deformation dependence by modelling the various elements of the ...

Experimental study of cluster effects in binary and ternary decays of low excited actinides

Malaza, Vusi David (Stellenbosch : Stellenbosch University, 2018-12)

ENGLISH ABSTRACT : The experimental study of rare decay modes of ternary fission performed by the FOBOS group at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, revealed a new ternary decay mode of low ...

Vacuum polarization energy for general backgrounds in one space dimension

Weigel, H. (Elsevier, 2017)

For field theories in one time and one space dimensions we propose an efficient method to compute the vacuum polarization energy of static field configurations that do not allow a decomposition into symmetric and anti-symmetric ...

Superfluid filaments of dipolar bosons in free space

Cinti, Fabio; Cappellaro, Alberto; Salasnich, Luca; Macri, Tommaso (American Physical Society, 2017)

We systematically investigate the zero temperature phase diagram of bosons interacting via dipolar interactions in three dimensions in free space via path integral Monte Carlo simulations with a few hundreds of particles ...

Examination of evidence for collinear cluster tri-partition

Pyatkov, Yu. V.; Kamanin, D. V.; Alexandrov, A. A.; Alexandrova, I. A.; Goryainova, Z. I.; Malaza, V.; Mkaza, N.; Kuznetsova, E. A.; Strekalovsky, A. O.; Strekalovsky, O. V.; Zhuchko, V. E. (American Physical Society, 2017)

Background: In a series of experiments at different time-of-flight spectrometers of heavy ions we have observed manifestations of a new at least ternary decay channel of low excited heavy nuclei. Due to specific features ...

Prethermalization and persistent order in the absence of a thermal phase transition

Halimeh, Jad C.; Zauner-Stauber, Valentin; McCulloch, Ian P.; De Vega, Ines; Schollwock, Ulrich; Kastner, Michael (American Physical Society, 2017)

We numerically study the dynamics after a parameter quench in the one-dimensional transverse-field Ising model with long-range interactions (∝1/rα with distance r), for finite chains and also directly in the thermodynamic ...

Snake fangs : 3D morphological and mechanical analysis by microCT, simulation, and physical compression testing

Du Plessis, Anton; Broeckhoven, Chris; Le Roux, Stephan G. (Oxford University Press, 2018)

This Data Note provides data from an experimental campaign to analyse the detailed internal and external morphology and mechanical properties of venomous snake fangs. The aim of the experimental campaign was to investigate ...

Emerging translational variance : vacuum polarization energy of the 𝜙6 kink

Weigel, H. (Hindawi, 2017-07-30)

We propose an efficient method to compute the vacuum polarization energy of static field configurations that do not allow decomposition into symmetric and antisymmetric channels in one space dimension. In particular, we ...

Simple models of three coupled PT-symmetric wave guides allowing for third-order exceptional points

Schnabel, Jan; Cartarius, Holger; Main, Jorg; Wunner, Gunter; Heiss, Walter Dieter (Czech Technical University--Prague, 2017-08)

We study theoretical models of three coupled wave guides with a PT-symmetric distribution of gain and loss. A realistic matrix model is developed in terms of a three-mode expansion. By comparing with a previously postulated ...

Proportional crosstalk for the iThemba LABS clover detector

Noncolela, S. P.; Bucher, T. D.; Lawrie, E. A.; Dinoko, T. R. S.; Easton, J. L.; Erasmus, N.; Lawrie, J. J.; Mthembu, S. H.; Mtshali, W. X.; Shirinda, O.; Orce, J. N. (Jagiellonian University, 2017-03)

Measurements of the proportional crosstalk were performed for the iThemba LABS segmented clover detector. More than 1000 crosstalk parameters were determined and a crosstalk correction algorithm was implemented successfully.

Chiral bands in 193Tl

Ndayishimye, J.; Lawrie, E. A.; Shirinda, O.; Easton, J. L.; Wyngaardt, S. M.; Bark, R. A.; Bvumbi, S. P.; Dinoko, T. R. S.; Jones, P.; Kheswa, N. Y.; Lawrie, J. J.; Majola, S. N. T.; Masiteng, P. L.; Negi, D.; Orce, J. N.; Papka, P.; Sharpey-Schafer, J. F.; Stankiewicz, M.; Wiedeking, M. (Jagiellonian University, 2017-03)

Since the introduction of chirality in nuclei, the search for chiral candidates in different mass regions has been a hot topic for about two decades. At iThemba LABS, a new chiral symmetry region, the thallium isotopes with ...

Optical tweezers for advanced microscopy

Erasmus, Anneke (Stellenbosch : Stellenbosch University, 2018-03)

ENGLISH SUMMARY: The integration of lasers into microscopy has enabled new areas of research and expanded existing ones. Not only can one now image samples to resolutions and contrast unheard of before lasers became ...

Investigating the photo-induced ultrafast insulator-metal phase transition in organic Cu(DCNQI)2 salts by ultrafast electron diffraction

Smit, Albert Bart (Stellenbosch : Stellenbosch University, 2018-03)

ENGLISH SUMMARY: This work presents the structural dynamics of the organic crystal Cu(DCNQI)2 (DCNQI: dicyanoquinonediimine) as it undergoes a photo-induced insulator-to-metal (IM) transition. Cu(DCNQI)2, a radical ion ...