Single Microwave-Photon Detector based on Superconducting Quantum Circuits

Transcription

1 17 th International Workshop on Low Temperature Detectors 19/July/2017 Single Microwave-Photon Detector based on Superconducting Quantum Circuits Kunihiro Inomata Advanced Industrial Science and Technology (AIST) Center for Emergent Matter Science, RIKEN

2 Collaborators Kazuki Koshino(Tokyo Medical and Dental Univ.) Zhirong Lin(CEMS, RIKEN) William D. Oliver(MIT Lincoln Laboratory) Jaw-Shen Tsai(Tokyo Univ. of Science/CEMS, RIKEN) Tsuyoshi Yamamoto(NEC Smart Energy Lab.) Yasunobu Nakamura(RCAST Univ. of Tokyo/CEMS, RIKEN) Prof. Koshino Dr. Lin Prof. Nakamura Dr. Yamamoto Prof. Tsai

3 Content 1. Motivation 2. Impedance-matched Λ system (artificial Λ-type atom) 3. Single microwave-photon detection 4. Summary

4 Quantum information processing with photons Frequency Wikipedia Optical photons (~ visible light) Microwave photons Wavelength Communication based on a single photon Quantum optics Science µm ~ GHz Single photon detectors Hamamatsu NIST NICT APD TES SSPD η ~ 30 % η > 90 % η > 90 % Coherent interaction between a qubit and a MW photon Flying qubit Quantum network based on MW photons, etc Single photon detector PRA Nature 2004.

5 Photon detectors in MW domain Harmonic oscillator mode [J. Wenner et al., PRL (2014)] MW nanobolometer [J. Govenius et al., PRL (2016)] Efficiency = Precise photon pulse shaping Time-dependent control of system parameters Efficiency ~ 0.56 (for ~200 photons ~ 1.1 zj) No single-photon sensitivity Dead time: ~100 µs Three-level cascaded system [S. R. Sathyamoorthy et al., PRL (2014)] Efficiency > 0.9 (theoretically) QND measurement Chain of transmons connected via circulators

6 Single photon detection in MW domain Impedance-matched Λ system K. Koshino, K. I. et al., PRL (2013) K. Inomata et al., PRL (2014) Qubit excited state Sensitivity to single MW photon Efficiency: ~ 0.66 (theory > 0.9) Dead time: short (reset pulse) Dark count: ~0.014 Free from photon pulse shaping No time-dependent control of params K. Koshino, K. I et al., PRA (2015) K. Inomata et al., Nat. Commun. (2016) Time-gate operation

7 Content 1. Motivation 2. Impedance-matched Λ system (artificial Λ-type atom) 3. Single microwave-photon detection 4. Summary

8 Impedance-matched Λ system 1D waveguide single photon wave packet Down-conversion ωω 1111 Raman transition with ~100% efficiency Impedance-matched Λ system Deterministic down-converter Single photon detector Single photon memory Perfect reflection Perfect absorption (Impedance matching) K. Koshino, PRA (2009, 2010).

9 Impedance-matched Λ system using dressed states Rotating frame at ω d Artificial Λ-type atom Probe Drive CPW resonator + Flux qubit Qubit drive P d, ω d Impedance matching Perfect absorption Deterministic down-conversion K. Koshino et al., PRL (2013). K. Koshino et al., NJP (2013). K. Inomata et al., PRL (2014). δδωω dd = ωω gggg ωω dd < 2χχ

10 Device Probe C λ/2 CPW resonator C c Drive Flux qubit Nb/SiO 2 /Si (0.05/0.3/299.7 µm) K. Inomata et al., PRB (2012) K. Inomata et al., PRL (2014) 0.5 µm C=15 ff C c =4 ff 50 µm 2 µm 50 µm

11 Absorption of incident microwave Probe Drive P d, ω d P p, ω p δδωω dd /2ππ = 64 MHz P p = dbm ( nn 0.013) ω d =5.397 GHz ~25 db!! ωω 41 ωω 31 ωω 42 K. Inomata et al., PRL (2014)

12 Down-converted spectrum Probe ωω 41 Down conversion ωω ss = ωω 42 ( ωω 41 δδωω dd ) Drive P d, ω d δδωω dd /2ππ = 64 MHz Input: GHz D.C.: GHz Perfect absorption Deterministic down-conversion Artificial Λ-type atom K. Inomata et al., PRL (2014)

13 Content 1. Motivation 2. Impedance-matched Λ system (artificial Λ-type atom) 3. Single microwave-photon detection 4. Summary Λ state

14 Z. R. Lin et al., Nat. Commun. (2014) Device & Measurement setup Resonator Qubit IN Readout visibility Rabi oscillations OUT Visibility ~ 90 %

15 Device & Measurement setup Triton 200 (Oxford) Base temperature: 10 mk Input MW line: 20 Output MW line with a HEMT: 4 GHzDAC (designed by J. Martinis) 1GSa/s Pulse shaping with ns precision

16 Pulse sequence for itinerant photon detection Pulse Sequence Initial state Λ state Readout state Qubit excited state Photon-detection efficiency Drive Signal Photon pulse Readout pulse Photon pulse (Gaussian pulse) Probability of the vacuum Pump Efficiency of photon detection : probability for click

17 K. Inomata et al., Nat. Commun. (2016) Itinerant photon detection using Z-matched Λ system Drive Signal Photon pulse Readout Pump Maximum Efficiency: 0.66 ±0.06 Absorption of photon. Efficiency > 0.9 is available!! Flip of qubit state due to Raman transition.

18 Dark count probability Nonadiabatic & thermal transition of a qubit Λ state K. Inomata et al., Nat. Commun. (2016) Drive ON OFF Nonadiabatic transition Depending on P d Constant N. T. T. T. Initial state Thermal transition

19 Reset of the system K. Inomata et al., Nat. Commun. (2016) Initial state Λ state Readout state Drive Signal π pulse Reset pulse Readout Optimal reset point Calculation Pump cf. without a reset pulse

20 Photon detection with a reset pulse π pulse 1 Reset 2 Photon 3 Readout Drive Signal Pump ~760 ns (~1.3 MHz) Pulse sequence Efficiency 0.667± ± ±0.059

21 Summary Demonstration of itinerant-photon detection using an artificial Λ-type atom. Single-photon detection efficiency = 0.66±0.06. Demonstration of reset of the system. Repetition time for the photon detection ~ 1.3 MHz. Dark count probability = 0.014±0.001.