19. Nov 2019
Phonon-number squeezing beyond the classical limit
Datum: 19. November 2019 |
11:00 –
12:00
Sprecher:
Jeremie Viennot, CNRS Paris
Veranstaltungsort: Heinzel Seminar Room / Office Bldg West (I21.EG.101)
to prepare them into quantum states. To go beyond the limitations of such linear coupling schemes, we quadratically couple the displacement of a 25 MHz oscillator to a superconducting qubit with a 4 GHz transition frequency [1]. This quadratic interaction enables direct control over the oscillator’s energy distribution. We squeeze this distribution by adiabatically adjusting dissipative reservoirs corresponding to driven qubit-oscillator sideband transitions. The large coupling strength between the qubit and the oscillator places the system in a dispersive ultra-strong coupling limit at large phonon numbers. We explore this new limit and we demonstrate the preparation and detection of non-classical states, characterized by a large mean phonon number and a comparatively small variance in phonon distribution [2]. These sub-Poissonian states could potentially be used to enhance the sensitivity of force detection.
[1] J. J. Viennot et al., Phys. Rev. Lett 121 (18), 183601 (2018)
[2] X. Ma et al. (in preparation)