Pramodh Senarath Yapa

PhD Student, Department of Physics, University of Alberta

Hello! My name's Pramodh (pronounced like Promote but with a d instead of a t ) and welcome to my mostly-about-research site! I study the physics of ultra-cold materials to understand how they tick at the quantum mechanical level; the specific systems I've looked at are superfluids, superconductors and Bose-Einstein condensates. You can find my CV here: download cv

I also spend a lot of time thinking about Science Communication and creative ways to reach the public (Hola, Dance Your PhD 2018!), so you can find that info here as well!

Publications.

Stabilized Pair Density Wave via Nanoscale Confinement of Superfluid 3-He

Physical Review Letters 124, 015301 – Published 3 January 2020

A.J. Shook, V. Vadakkumbatt, P. Senarath Yapa, C. Doolin, R. Boyack, P.H. Kim, G.G. Popowich, F. Souris, H. Christani, J. Maciejko, and J.P. Davis

Superfluid 3-He under nanoscale confinement has generated significant interest due to the rich spectrum of phases with complex order parameters that may be stabilized. Experiments have uncovered a variety of interesting phenomena, but a complete picture of superfluid 3-He under confinement has remained elusive. Here, we present phase diagrams of superfluid 3-He under varying degrees of uniaxial confinement, over a wide range of pressures, which elucidate the progressive stability of both the A phase, as well as a growing region of stable pair density wave state.

Read the PRL | Read the arXiv preprint | Read the Phys.org news release

Impact of Nonlocal Electrodynamics on the Flux Noise and Inductance of Superconducting Wires

Physical Review Applied 11, 024041 – Published 15 February 2019

P. Senarath Yapa, Tyler Makaro, and Rogério de Sousa

We present exact numerical calculations of the supercurrent density, inductance, and impurity-induced flux noise of cylindrical superconducting wires in the nonlocal Pippard regime, which occurs when the Pippard coherence length is greater than the London penetration depth. In this regime, the supercurrent density displays a peak away from the surface and changes sign inside the superconductor, signaling a breakdown of the usual approximation of local London electrodynamics with a renormalized penetration depth. Our calculations show that the internal inductance and the bulk flux noise power are enhanced in nonlocal superconductors. In contrast, the kinetic inductance is reduced and the surface flux noise remains the same. As a result, impurity spins in the bulk may dominate the flux noise in superconducting qubits in the Pippard regime, such as the ones using aluminum superconductors with a large electron mean free path.

Read the PRApplied | Read the arXiv preprint |
Read the Advances in Engineering article

Education.

  • 2018-Present

    University of Alberta, Edmonton AB, Canada

    PhD Student in Condensed Matter Theory, Department of Physics

    Thesis: Exotic Phases of Confined Superfluid 3-He Co-supervised by Prof. Joseph Maciejko and Prof. Frank Marsiglio

  • 2015-2018

    University of Victoria, Victoria BC, Canada

    MSc. in Condensed Matter Theory, Department of Physics

    Thesis: Non-Local Electrodynamics of Superconducting Wires: Implications for Flux Noise and Inductance supervised by Prof. Rogério de Sousa

  • 2010-2015

    Carleton University, Ottawa ON, Canada

    Honours BSc. in Theoretical Physics and Minor in Mathematics, Department of Physics

    Honours Thesis: Supersymmetry Phenomenology Supervised by Prof. Thomas Gregoire

Selected Presentations.

Contact.

pramodhsy(at)ualberta(dot)ca
  • 3-145,
  • Centennial Center for Interdisciplinary Science (CCIS),
  • Department of Physics,
  • University of Alberta
  • Edmonton, AB
  • Canada, T6H 2T5

The University of Alberta respectfully acknowledges that we are located on Treaty 6 territory, a traditional gathering place for diverse Indigenous peoples including the Cree, Blackfoot, Métis, Nakota Sioux, Iroquois, Dene, Ojibway/ Saulteaux/Anishinaabe, Inuit, and many others whose histories, languages, and cultures continue to influence our vibrant community.