J. Salmilehto

Quantum Memristors with Superconducting Circuits

  1. J. Salmilehto,
  2. F. Deppe,
  3. M. Di Ventra,
  4. M. Sanz,
  5. and E. Solano
Memristors are resistive elements retaining information of their past dynamics. They have garnered substantial interest due to their potential for representing a paradigm change in
electronics, information processing and unconventional computing. Given the advent of quantum technologies, a design for a quantum memristor with superconducting circuits may be envisaged. Along these lines, we introduce such a quantum device whose memristive behavior arises from quasiparticle-induced tunneling when supercurrents are cancelled. For realistic parameters, we find that the relevant hysteretic behavior may be observed using current state-of-the-art measurements of the phase-driven tunneling current. Finally, we develop adequate methods to quantify the memory retention in this system.
arxiv pdf

Highly controllable qubit-bath coupling based on a sequence of resonators

  1. P. J. Jones,
  2. J. Salmilehto,
  3. and M. Möttönen
Combating the detrimental effects of noise remains a major challenge in realizing a scalable quantum computer. To help to address this challenge, we introduce a model realizing a controllable
qubit-bath coupling using a sequence of LC resonators. The operating principle is similar to that of a recently proposed coplanar-waveguide cavity (CPW) system, for which our work introduces a complementary and convenient experimental realization. The lumped-element model utilized here provides an easily accessible theoretical description. We present analytical solutions for some experimentally feasible parameter regimes and study the control mechanism. Finally, we introduce a mapping between our model and the recent CPW system.
arxiv pdf