Mechanical resonators towards quantum limit:

NEMS group

together withNANO,

THEORY, KVANTTI

Mika Sillanpää assoc. prof., team leaderJuha-Matti Pirkkalainen MSc, grad studentGolam Kibria Chowdhury MSc, grad studentJaakko Sulkko undergrad studentErno Damskägg undergrad student

Mika Sillanpää, Low Temperature Laboratory

Quantum limit of moving objects Optomechanics

Cohadon, PRL 83, 3174 (1999).Gigan, Nature 444, 67 (2006).Kippenberg, Science 321, 1173 (2008).

wc /(2 ) p ~ 1014 Hzwm /(2 ) p ~ 106 Hz

gc/(2 ) p ~ 106 Hzgm/(2 ) p ~ 100 Hz

Mika Sillanpää, Low Temperature Laboratory

Circuit optomechanics Microwave resonator

(”cavity”) with a movable boundary condition

Like an LC circuit with time-dependent capacitors

Mika Sillanpää, Low Temperature Laboratory

Circuit optomechanics High-impedance ”cavity” Focused Ion Beam (FIB) cutting of narrow vacuum gaps

(~10 nm)

Mika Sillanpää, Low Temperature Laboratory

Circuit optomechanics Mechanical microwave

amplification

Coupling of mechanical resonators via cavity “quantum bus”

F. Massel et al, Nature, 480, 351 (2011).

Mika Sillanpää, Low Temperature Laboratory

Cavity QED with phonons “Artificial atom” (transmon qubit) coupled to both

photonic and phononic cavity

Mika Sillanpää, Low Temperature Laboratory

Cavity QED with phonons Phonon Stark shift

ultrastrong light-matter coupling

Mika Sillanpää, Low Temperature Laboratory

Cavity QED with phonons Electromechanical Rabi

flops Photon – phonon

conversion

Motional sidebands “Trapped-ion” experiments

Mika Sillanpää, Low Temperature Laboratory

Future Coupling of micromechanical

resonators via ”cavity bus” Coherent phonon transfer in time domain Slowing down (and superluminal!)

microwave pulses Coupling to Josephson junction qubits

Increase coupling further Create non-classical states of purely

mechanical object Circuit optomechanics with graphene

large zero-point amplitude xZP ~ 1 pm cool it near the ground state Single-phonon strong coupling

Mika Sillanpää, Low Temperature Laboratory

Mechanical resonators towards quantum limit:

Circuit optomechanics Mechanical microwave amplifier

Quantum-limited operation predicted Sideband cooling down to 1.8 phonon

quanta Hybridization of multiple phonons and a photon

phonon bus, creation of entanglement..? Phonon QED

Motional sidebands of qubit spectral line Sideband Rabi oscillations Prospects

Creation of non-classical states of slowly moving objects

Long-lived quantum memory

Mika Sillanpää, NEMS group