Department of Physics

Prof AE Botha

College of Science, Engineering and Technology
School of Science
Department: Physics
Associate Professor
Tel: 011 670 9077
Fax: 011 670 3643
E-mail: bothaae@unisa.ac.za

Qualifications

  • Ph.D. Physics (University of Western Ontario, Canada)
  • M.S. Physics (Denver University, U.S.A.)
  • M.Sc. Physics (Rhodes University)
  • B.Sc. (HONS) Physics (Rhodes University)
  • B.Sc. Physics and Electronics (Rhodes University)

Fields of academic interests

Research interests

  • Chaos and nonlinear dynamics
  • Josephson junctions
  • Synchronization phenomena

Field of Specialisation

  • Computational physics
  • Fluctuation theory
  • Classical molecular dynamics

Journal articles

  1. Yu M Shukrinov, I R Rahmonov, K V Kulikov, A E Botha, A Plecenik, P Seidel and W Nawrocki, Modeling of LC-shunted intrinsic Josephson junctions in high-Tc superconductors, Supercond. Sci. Technol. 30, 024006 (2017). 
  2. A. E. Botha, Characteristic distribution of finite-time Lyapunov exponents for chimera states, Scientific Reports 6, 29213 (2016).
  3. A. E. Botha, Yu. M. Shukrinov and M. R. Kolahchi, A Farey staircase from the two-extremum return map of a Josephson junction, Nonlinear Dynamics 84, 1363 (2016).
  4. Yu. M. Shukrinov, H. Azemtsa-Donfack, I. R. Rahmonov and А. E. Botha, Cascade of parametric resonances in coupled Josephson junctions, Low Temperature Physics 42, 123 (2016).
  5. Yu. M. Shukrinov, H. Azemtsa-Donfack and А. E. Botha, Chaos induced by coupling between Josephson junctions, Pis’ma v ZhETF 101, 269 (2015).
  6. W. Dednam and A. E. Botha, Optimized shooting method for finding the periodic orbits in nonlinear systems, Engineering with Computers, 31, 749 (2015).
  7. A. E. Botha, Yu. M. Shukrinov, S. Yu. Medvedeva, and M. R. Kolahchi, Structured Chaos in 1-D Stacks of Intrinsic Josephson Junctions Irradiated by Electromagnetic Waves, Journal of Superconductivity and Novel Magnetism, 28, 349 (2015).
  8. Yu. M. Shukrinov, A. E. Botha, S. Yu. Medvedeva, M. R. Kolahchi, and A. Irie, Structured chaos in a devil’s staircase of the Josephson junction, Chaos 24, 033115 (2014).
  9. A. E. Botha, Electromagnetic analog of 3-d autonomous ordinary differential equations with quadratic nonlinearities, Int. J. Bifurcation Chaos 24, 1450070 (2014).
  10. Yu. M. Shukrinov, S. Yu. Medvedeva, A. E. Botha, M. R. Kolahchi, and A. Irie, Devil’s staircases and continued fractions in Josephson junction, Phys. Rev. B 88, 214515 (2013).
  11. M. R. Kolahchi, Yu. M. Shukrinov, M. Hamdipour, A. E. Botha and M. Suzuki, Some chaotic features of intrinsically coupled Josephson junctions, Physica C: Superconductivity and its Applications 487, 234 (2013). 
  12. A. E. Botha, Yu. M. Shukrinov and M. R. Kolahchi, Onset of chaos in intrinsic Josephson junctions, Chaos, Solitons & Fractals 48, 32 (2013).
  13. Y. M. Shukrinov, M. Hamdipour, M. R. Kolahchi, A.E. Botha and M. Suzuki, Manifestation of resonance-related chaos in coupled Josephson junctions, Phys. Lett. A 376, 3609 (2012).
  14. A. E. Botha, General R-matrix approach for integrating the multiband k p equation in layered semiconductor structures, Computer Physics Communications 183, 197 (2012).

Paper presentations

  • Yu M Shukrinov, I R Rahmonov, K V Kulikov, A E Botha, A Plecenik, P Seidel and W Nawrocki, Modeling of LC-shunted intrinsic Josephson junctions in high-Tc superconductors, Proceedings of HTS Modelling workshop, 15-17 June 2016, Bologna, Italy.
  • A. E. Botha, Yu. M. Shukrinov and M. R. Kolahchi, Chaos and regularity in driven intrinsic Josephson junctions, Proceedings of the 8th Chaotic Modeling and Simulation International Conference, 26-29 May 2015, Henri Poincaré Institute, Paris, France.
  • W. Dednam and A. E. Botha, Evaluation of Kirkwood-Buff integrals via finite size scaling: a large scale molecular dynamics study, Journal of Physics: Conference Series 574, 012092 (2015). Proceedings of the 3rd International Conference on Mathematical Modeling in Physical Sciences, 28–31 August 2014, Madrid, Spain.
  • A. E. Botha, Yu. M. Shukrinov and M. R. Kolahchi, Quasi-periodic and frequency-locking routes to chaos in intrinsic Josephson junctions, Proceedings of the 6th Chaotic Modeling and Simulation International Conference, 11-14 June, Yeditepe University, Istanbul, Turkey.
  • A. E. Botha and G. Qi, Analysis of the triple pendulum as a hyperchaotic system, Proceedings of the 5th Chaotic Modelling and Simulation International Conference, 12-15 June 2012, President Hotel, Athens, Greece.

Projects

  • Investigating Laser Cooling of Doped Sodium Aluminium Silicate Crystals
  • Detrended fluctuation analysis of  frustrated systems
  • Spontaneous synchronization and control of networks of intrinsic Josephson junctions

Other

Membership

  • Member, Institute of Physics (IOP), United Kingdom
  • Member, Canadian Institute of Physics, Canada

Invited Talks

Detecting criticality and ‘close to the edge’ behaviour in nonlinear systems of phase oscillators – An invited talk presented in the Department of Physics at the Vaal University of Technology, Vanderbijlpark, South Africa (9 November 2016).