

- Andreev Reflection in Superfluid He-3: A Probe for Quantum Turbulence
Bradley et al., Annual Review of Condensed Matter Physics Vol. 8: 407-430 (2017) - Operating Nanobeams in a Quantum Fluid
Bradley et al., Nature Scientific Reports 7, 4876 (2017) - Single Quantum Level Electron Turnstile
D.M.T. Van Zanten et al., Phys. Rev. Lett. 116 166801 (2016) - Topological Superconductivity and High Chern Numbers in 2D Ferromagnetic Shiba Lattices
J. Röntynen, T. Ojanen, Phys. Rev. Lett. 114 236803, (2015) - Squeezing of Quantum Noise of Motion in a Micromechanical Resonator
J.-M. Pirkkalainen et al., Phys. Rev. Lett 115, 24 (2015) - Direct-current superconducting quantum interference devices for the readout of metallic magnetic calorimeters
S. Kempf, A. Ferring, A. Fleischmann, C. Enss, Supercond. Sci. Technol. 28 , 045008 (2015)
Enhancing Optomechanical Coupling via the Josephson Effect
Heikkila, T. T., Massel, F., Tuorila, J., Khan, R. and Sillanpaa, M. A.Cavity optomechanics is showing promise for studying quantum mechanics in large systems. However, the smallness of the radiation-pressure coupling is a serious hindrance. Here we show how the charge tuning of the Josephson inductance in a single-Cooper-pair transistor can be exploited to arrange a strong radiation-pressure-type coupling g0 between mechanical and microwave resonators. In a certain limit of parameters, such a coupling can also be seen as a qubit-mediated coupling of two resonators. We show that this scheme allows reaching extremely high g0. Contrary to the recent proposals for exploiting the nonlinearity of a large radiation-pressure coupling, the main nonlinearity in this setup originates from a cross-Kerr type of coupling between the resonators, where the cavity refractive index depends on the phonon number. The presence of this coupling will allow accessing the individual phonon numbers via the measurement of the cavity.
Physical Review Letters, 112, 203603/1-6 (2014)
doi: 10.1103/PhysRevLett.112.203603