Selected Publications

- 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)

## Squeezing of Quantum Noise of Motion in a Micromechanical Resonator

*J.-M. Pirkkalainen, E. Damskägg, M. Brandt, F. Massel, M.A. Sillanpää*

A pair of conjugate observables, such as the quadrature amplitudes of harmonic motion, have fundamental fluctuations that are bound by the Heisenberg uncertainty relation. However, in a squeezed quantum state, fluctuations of a quantity can be reduced below the standard quantum limit, at the cost of increased fluctuations of the conjugate variable. Here we prepare a nearly macroscopic moving body, realized as a micromechanical resonator, in a squeezed quantum state. We obtain squeezing of one quadrature amplitude 1.1±0.4 dB below the standard quantum limit, thus achieving a long-standing goal of obtaining motional squeezing in a macroscopic object.

*Phys. Rev. Lett*

**115**, 24 (2015)doi:

*10.1103/PhysRevLett.115.243601*