Juuso Manninen

Hybrid optomechanical superconducting qubit system

  1. Juuso Manninen,
  2. Robert H. Blick,
  3. and Francesco Massel
We propose an integrated nonlinear superconducting device based on a nanoelectromechanical shuttle. The system can be described as a qubit coupled to a bosonic mode. The topology of
the circuit gives rise to an adjustable qubit/mechanical coupling, allowing the experimenter to tune between linear and quadratic coupling in the mechanical degrees of freedom. Owing to its flexibility and potential scalability, the proposed setup represents an important step towards the implementation of bosonic error correction with mechanical elements in large-scale superconducting circuits. We give preliminary evidence of this possibility by discussing a simple state-swapping protocol that uses this device as a quantum memory element.
arxiv pdf

Semiclassical dynamics of a superconducting circuit: chaotic dynamics and fractal attractors

  1. Davide Stirpe,
  2. Juuso Manninen,
  3. and Francesco Massel
In this article, we study the semiclassical dynamics of a superconducting circuit constituted by two Josephson junctions in series, in the presence of a voltage bias. We show that the
equations of motion describing the superconducting phase correspond to those controlling the dynamics of a planar rotor with an oscillating pivot and, consequently, to those of a Kapitza pendulum in the absence of gravity. In addition, we show that the system exhibits a rich dynamical behavior with chaotic properties and provide insight into its attractor’s fractal nature.
arxiv pdf