Overview. Tasks: 1.1. Realization of a direct coherent microwave-to-optical link

Transcription

1 Overview Optical cavity Microwave cavity Mechanical resonator Tasks: 1.1. Realization of a direct coherent microwave-to-optical link 1.2 Development of large gain-bandwidth product microwave amplifiers with minimal added noise

2 Outline 1. Progress on realization of coherent microwave-to-optical link 1. Microwave amplification in the reversed dissipation regime of cavity optomechanics 2. Wideband Josephson parametric amplifiers

3 Cavity electro-optical converter Electro-optical coefficient enables to coupling electric fields to optical fields. H int = hg( b + b ) a a λ optical 1 μm Free space optical λ μ 10 cm Free space microwave Girvin et al. Use structures that provide small mode volume for microwave mode. Tsang, PRA

4 Cavity electro-optical converter Microwave feedline SiO2 LiNbO3 Microstrip resonator WGM microring resonator Substrate TiN Coupling waveguide Microwave electric field between the two electrodes 4

5 Fabrication of high Q microresonators from LiNbO3 Cleaning, annealing LN thin film (500nm) Al LN SiO2 LN SiO2 (100nm) 1 SiO2 Al LN a-c (600nm) LN SiO2 2 SiO2 Al LN 3 LN LN Photoresist a-c Al SiO2 SiO2 5 LN LN Photoresist a-c Al SiO2 SiO2 4 LN LN Photoresist a-c Al SiO2 SiO2 6 LN LN Photoresist a-c Al SiO2 SiO2 7 LN LN a-c Al SiO2 SiO2 8 LN LN a-c Al 9 SiO2 SiO2 1, 2: SiO2 and amorphous carbon mask deposition 3, 4: ebeam lithography 5, 6, 8: a-c, SiO2 and LN etching 7, 9: PR removal and a-c stripping LN LN Al SiO2 SiO2

6 Fabrication of high Q microresonators from LiNbO3 Fabricated first devices in LNOI and established the etching processes Fabricated first integrated resonators

7 Outline 1. Progress on realization of coherent microwave-to-optical link 2. Microwave amplification in the reversed dissipation regime of cavity optomechanics 3. Wideband Josephson parametric amplifiers

8 The reversed dissipation regime Optomechanical interactions Coherent exchange of quanta, cooling Electromagnetic mode damps mechanical oscillator on red sideband Amplification and two mode squeezing Electromagnetic mode amplifies mechanical oscillator on blue sideband Conventional Dissipation hierarchy: m eff eff Reversed dissipation hierarchy : m Change in mechanical damping rate, becomes change in optical rate. A. Nunnenkamp, Sudhir, Feofanov, Roulet, Kippenberg, PRL 113 (023604),

9 The reversed dissipation regime Reversed dissipation hierarchy : m Mechanics amplifies electromagnetic mode on blue sideband DBA eff eff Change in mechanical damping rate, becom change in optical rate. Change in the optical electromagnetic damping (mechanical damping) g n g n ( / 2) ( ) ( / 2) ( ) 2 2 eff 0 p eff 0 p eff m eff m Change in the electromagnetic resonance freq. g n ( ) g n ( ) DBA ( / 2) ( ) ( / 2) ( ) 2 2 eff 0 p m eff 0 p m eff m eff m S 11 Modified cavity response c ( ) 1 ( ) / 2 i ( ) 0 c DBA 0 DBA A. Nunnenkamp, Sudhir, Feofanov, Roulet, Kippenberg, PRL 113 (023604),

10 Amplification in the reversed dissipation regime Amplification scheme The system operates as phase preserving parametric amplifier Gain of the amplifier (amplification of signal) A. Nunnenkamp, Sudhir, Feofanov, Roulet, Kippenberg, PRL 113 (023604), 2014 C. M. Caves, Phys. Rev. D 26, 1817 (1982). 10

11 Noise of the RDR optomechanical amplifier Added noise G m k Phase preserving amplifier Added noise by amplifier N 1 4Cneff 2 1 n 2 eff ( C 1) 2 Providing a dissipative but cold mechanical oscillator therefore realizes quantum limited phase preserving amplifier based on a mechanical oscillator A. Nunnenkamp, Sudhir, Feofanov, Roulet, Kippenberg, PRL 113 (023604), 2014 C. M. Caves, Phys. Rev. D 26, 1817 (1982). 11

12 Two-mode implementation of the reversed dissipation regime A. Nunnenkamp, Sudhir, Feofanov, Roulet, Kippenberg, PRL 113 (023604), 2014 Teufel, Lehnert, Nature (2011) 12

13 Two-mode implementation of the reversed dissipation regime m 2 Realization of RDR: One mode established the RDR with respect to the amplifier mode: G eff = G m (C 2 +1) 2 4G2 m,eff 2 / 2 for C2 1 2m 1 4Cneff 2 1 N n 2 eff ( C 1) 2 A. Nunnenkamp, Sudhir, Feofanov, Roulet, Kippenberg, PRL 113 (023604), 2014 Teufel, Lehnert, Nature (2011) 13

14 Two-mode implementation of the reversed dissipation regime Required parameters are feasible with superconducting microwave circuits w c / 2p k / 2p W m / 2p G m / 2p g 0 / 2p P in (= P 2,in ) Proposed 7.5 GHz 10 khz 1 MHz 50 Hz 100 Hz 0.3 nw Teufel et al [1] 7.5 GHz 170 khz 10 MHz 30 Hz 230 Hz 100 nw A particular challenge: to fabricate an optomechanical system with multiple EM modes coupled to a mechanical element and with precisely engineered parameters (e.g. very dissimilar coupling rates) A. Nunnenkamp, Sudhir, Feofanov, Roulet, Kippenberg, PRL 113 (023604), 2014 Teufel, Lehnert, Nature (2011) 14

15 Dual circuit-electromechanical EPFL Established modified fabrication process to fabricate drum resonator (following R. Simmonds, NIST approach) Smallest separation 30 nm Demonstrated dual transducers

16 Fabrication flow , 3, 9: metal and sacrificial layer (Si) deposition 2, 8, 10: metal and Si etch 4, 5: planarization of Si layer (for split-plate drums) 6, 7: lithography to open Si layer (with reflow) 11: releasing the drum capacitor 16

17 Dual circuit-electromechanical circuit LC 1 (amplifier mode) LC 2 (cooling mode) Feedline (microstrip) m 2 D. Toth, N. Bernier A. Feofanov, TJK (unpublished) 17

18 Testing of dual circuit-electromechanical circuit D. Toth, N. Bernier A. Feofanov, TJK (unpublished)

19 Measurement setup D. Toth, N. Bernier A. Feofanov, TJK (unpublished) 19

20 Experimental characterization of dual circuit electromechanical devices Device characterization /2 /2 w /2 1 1 /2 g /2 2 / 2p / GHz 115 khz 5.4 GHz 4.4 MHz 5 MHz ~ 100 Hz ~ 80 Hz m m With these parameters we can easily damp the mechanics to Γ eff ~ 2π 750 khz 6κ 1 => RDR 2 m D. Toth, N. Bernier A. Feofanov, TJK (unpublished) S. Weis et al, Science (2010) J. D. Teufel et al. Nature (2011) 20

21 Experimental characterization of dual circuit electromechanical devices g 2 1 MHz Ω m P cool P probe OMIT peak S. Weis et al, Science (2010) J. D. Teufel et al. Nature (2011) 21

22 Experimental characterization of dual circuit electromechanical devices D. Toth, N. Bernier A. Feofanov, TJK (unpublished) Preparation of a cold dissipative reservoir by increasing Γ eff / 2π to 500 khz ~ 2 eff 2 / Create close to Markovian dissipative bath for electromagnetic mode m 2

23 Mechanical spring effect Fix power of pump (5 dbm) and sweep detuning g n ( ) g n ( ) DBA ( / 2) ( ) ( / 2) ( ) S eff 0 p m eff 0 p m eff m eff m c ( ) 1 ( ) / 2 i ( ) D. Toth, N. Bernier A. Feofanov, TJK (unpublished) 0 c DBA 0 DBA

24 Electromagnetic dynamical backaction by dissipative reservoir Fix power of pump (5 dbm) and sweep detuning S DBA 11 g n g n ( / 2) ( ) ( / 2) ( ) 2 2 eff 0 p eff 0 p eff m eff m c ( ) 1 ( ) / 2 i ( ) 0 c DBA 0 Demonstrates electromagnetic control over the cavity damping rate, via mechanical dissipative reservoir D. Toth, N. Bernier A. Feofanov, TJK (unpublished) DBA 24

25 Deamplification by mechanical reservoir engineering Pump detuned on red sideband m Depth of resonance: S 0 c 11( 0) 0 c DBA DBA D. Toth, N. Bernier A. Feofanov, TJK (unpublished) 25

26 Amplification by mechanical reservoir engineering A blue-detuned pump reduces bandwidth and increases gain. Depth of resonance: S 0 c 11( 0) 0 c DBA DBA D. Toth, N. Bernier A. Feofanov, TJK (unpublished) 26

27 Amplification by mechanical reservoir engineering G 20 db N HEMT 20 quanta N 12 quanta Signal to noise improvement demonstrates that the optomechanical amplifier has an improved Noise figure compared to a HEMT with T noise 5 K. 27

28 Subthreshold Maser using a mechanical dissipative reservoir Linewidth narrows as we increase pump power (blue side). Below threshold: S 0 c 11( 0) 0 c DBA DBA Analogous to dynamical backaction parametric instability of a mechanical mode, but acting on the microwave cavity D. Toth, N. Bernier A. Feofanov, TJK (unpublished)

29 Maser using a mechanical dissipative reservoir Above threshold Above this threshold, the noise turns into self-sustained oscillations in the cavity. S 0 c 11( 0) 0 c DBA DBA First observation of dynamical backaction of an electromagnetic mode D. Toth, N. Bernier A. Feofanov, TJK (unpublished)

30 Dynamical backaction amplification using radiation pressure 1969: Radiation pressure Parametric instability: theory Braginsky JETP 1969 (between mech. oscillator&microwave H g a a bˆ bˆ ˆ 0 ˆ( ) 2005: Radiation pressure parametric instability: Microresonators: Kippenberg,Vahala Phys. Rev. Lett : Radiation pressure Parametric instability: LIGO (macroscopic mirrors): Evans et al. Phys. Rev. Lett : Radiation pressure Parametric instability: Dynamical backaction amplification of a microwave mode

31 Dual circuit-electromechanical EPFL Optomechanical reservoir engineering Realized electro-mechanics in the reversed dissipation regime Demonstrates changing electromagnetic cavity properties via dissipative mechanical reservoir Amplification and deamplification shown Maser action observed, e.g. synthesis low noise microwaves diss More generally, realized a new class of dissipative optomechanical interaction: Quantum limited infinite gain bandwidth product amplifiers Nonreciprocal devices (e.g. circulator, isolators, )

32 Outline 1. Progress on realization of coherent microwave-to-optical link 2. Microwave amplification in the reversed dissipation regime of cavity optomechanics 3. Wideband Josephson parametric amplifiers

33 Parametric amplifier: single SQUID (D1.4) Fabricated using the trilayer technology of VTT, Otaniemi, Finland Largest stable gain around 23 db with a bandwidth of 2 MHz Tn iquoems 2nd review, Aalto University

34 Lumped element parametric device iquoems 2nd review, Aalto University

35 Coherence induced by vacuum fluctuations iquoems 2nd review, Aalto University

36 Experimental setup - Vector signal analyzer - Quadrature components digitized at 50 MHz rate - Digital band filtering and correlations with FFT iquoems 2nd review, Aalto University

37 Correlations in a two pump configuration 2 p res ( ) p p res 0 2 res ( ) p 2 2 p iquoems 2nd review, Aalto University

38 Parametric gain with two pumps res res iquoems 2nd review, Aalto University

39 Higher order correlations - Reflections across the pump frequencies - Importance goes down as distance to resonance frequencies increases iquoems 2nd review, Aalto University

40 Solution with two pumps Iterative solution: Two-mode squeezing: Beam splitter correlations : iquoems 2nd review, Aalto University

41 Bright and dark modes a a 1 a 2 = Bright state a 1 a 2 Dark state a 1 a 2 iquoems 2nd review, Aalto University

42 Vacuum induced coherence Pump 1 Pump 2 A B H b a a b a a H b a a b a a C D 2 Correct phase: no time development B i.e. dark state C Coherence due to the same quantum fluctuation taking part in the generation of the pairs Large DOS population can be zero 0 1 A D iquoems 2nd review, Aalto University

43 Noise power measurements (low power) r res iquoems 2nd review, Aalto University

44 Noise power measurements (low & high power) iquoems 2nd review, Aalto University

45 Mode correlators I a a 1 a b a a d a a iquoems 2nd review, Aalto University

46 Mode correlators II Lähteenmäki, P., Paraoanu, G. S., Hassel, J. & Hakonen, P. J., submitted to Nature Communications iquoems 2nd review, Aalto University

47 Phase of the dark and bright states b e a e a i1 i2 [ ] cos [2 ] sin [2 ] iquoems 2nd review, Aalto University

48 Which path - which color information In our case: two slits open when two pumps are on the system does not know from which pump the photon came - Our which path is in frequency space - Information can be obtained by varying pumps in time P. Bertet, S. Osnaghi, iquoems A. Rauschenbeutel, 2nd review, Aalto University G. Nogues, A. Auffeves, M. Brune, J. M. Raimond & S. Haroche, Nature 411, 166 (2001)

49 Pulsed pumps with tuned overlap Base line for b b contains DCE power iquoems 2nd review, Aalto University

50 Final design of the parametric amplifier - Matching separate from the SQUID chip: easier to make proper matching and achieve gain iquoems 2nd review, Aalto University