A major challenge to the scalability of cryogenic computing platforms is the heat load associated with the growing number of electrical cable connections between the superconducting circuitry and the room-temperature environment. Compared with electrical cables, optical fibres have significantly lower thermal conductivity and are widely used in modern telecommunications. However, optical modulation at cryogenic temperatures remains relatively unexplored. Here we report the cryogenic electro-optical readout of a superconducting electromechanical circuit using a commercial titanium-doped lithium niobate modulator. We demonstrate coherent spectroscopy by measuring optomechanically induced transparency and incoherent thermometry by encoding the mechanical sidebands in an optical signal. We also show that our modulators can maintain their room-temperature Pockels coefficient at 800 mK. Further optimization of the modulator design—for example, by using longer waveguides and materials with a higher Pockels coefficient—could reduce the added noise of our setup to similar levels as current semiconductor microwave amplifiers.
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The data used to produce the plots within this paper are available on Zenodo (https://doi.org/10.5281/zenodo.4449948). All other data used in this study are available from the corresponding author on reasonable request.
The code used to produce the plots within this paper is available on Zenodo (https://doi.org/10.5281/zenodo.4449948).
Winzer, P. J., Neilson, D. T. & Chraplyvy, A. R. Fiber-optic transmission and networking: the previous 20 and the next 20 years. Opt. Express 26, 24190–24239 (2018).
Kachris, C. & Tomkos, I. A Survey on optical interconnects for data centers. IEEE Commun. Surveys Tuts. 14, 1021–1036 (2012).
Cheng, Q., Bahadori, M., Glick, M., Rumley, S. & Bergman, K. Recent advances in optical technologies for data centers: a review. Optica 5, 1354–1370 (2018).
Blumenthal, D. J. et al. All-optical label swapping networks and technologies. J. Lightwave Technol. 18, 2058–2075 (2000).
Thomson, D. et al. Roadmap on silicon photonics. J. Opt. 18, 073003 (2016).
Sun, C. et al. Single-chip microprocessor that communicates directly using light. Nature 528, 534–538 (2015).
Miller, D. A. B. Optical interconnects to silicon. IEEE J. Sel. Topics Quantum Electron. 6, 1312–1317 (2000).
Devoret, M. H. & Schoelkopf, R. J. Superconducting circuits for quantum information: an outlook. Science 339, 1169–1174 (2013).
Martinis, J. M., Devoret, M. H. & Clarke, J. Quantum Josephson junction circuits and the dawn of artificial atoms. Nat. Phys. 16, 234–237 (2020).
Blais, A., Girvin, S. M. & Oliver, W. D. Quantum information processing and quantum optics with circuit quantum electrodynamics. Nat. Phys. 16, 247–256 (2020).
Arute, F. et al. Quantum supremacy using a programmable superconducting processor. Nature 574, 505–510 (2019).
Krinner, S. et al. Engineering cryogenic setups for 100-qubit scale superconducting circuit systems. EPJ Quantum Technol. 6, 2 (2019).
Lauk, N. et al. Perspectives on quantum transduction. Quantum Sci. Technol. 5, 020501 (2020).
Lecocq, F. et al. Control and readout of a superconducting qubit using a photonic link. Nature 591, 575–579 (2021).
Jiang, W. et al. Lithium niobate piezo-optomechanical crystals. Optica 6, 845–853 (2019).
Jiang, W. et al. Efficient bidirectional piezo-optomechanical transduction between microwave and optical frequency. Nat. Commun. 11, 1166 (2020).
Bartholomew, J. G. et al. On-chip coherent microwave-to-optical transduction mediated by ytterbium in YVO4. Nat. Commun. 11, 3266 (2020).
Higginbotham, A. P. et al. Harnessing electro-optic correlations in an efficient mechanical converter. Nat. Phys. 14, 1038–1042 (2018).
Forsch, M. et al. Microwave-to-optics conversion using a mechanical oscillator in its quantum ground state. Nat. Phys. 16, 69–74 (2020).
Arnold, G. et al. Converting microwave and telecom photons with a silicon photonic nanomechanical interface. Nat. Commun. 11, 4460 (2020).
Andrews, R. W. et al. Bidirectional and efficient conversion between microwave and optical light. Nat. Phys. 10, 321–326 (2014).
Chu, Y. & Gröblacher, S. A perspective on hybrid quantum opto- and electromechanical systems. Appl. Phys. Lett. 117, 150503 (2020).
Mirhosseini, M., Sipahigil, A., Kalaee, M. & Painter, O. Superconducting qubit to optical photon transduction. Nature 588, 599–603 (2020).
Tsang, M. Cavity quantum electro-optics. Phys. Rev. A 81, 063837 (2010).
Rueda, A. et al. Efficient microwave to optical photon conversion: an electro-optical realization. Optica 3, 597–604 (2016).
Rueda, A., Sedlmeir, F., Kumari, M., Leuchs, G. & Schwefel, H. G. L. Resonant electro-optic frequency comb. Nature 568, 378–381 (2019).
Hease, W. et al. Bidirectional electro-optic wavelength conversion in the quantum ground state. PRX Quantum 1, 020315 (2020).
Fan, L. et al. Superconducting cavity electro-optics: a platform for coherent photon conversion between superconducting and photonic circuits. Sci. Adv. 4, eaar4994 (2018).
McKenna, T. P. et al. Cryogenic microwave-to-optical conversion using a triply resonant lithium-niobate-on-sapphire transducer. Optica 7, 1737–1745 (2020).
Holzgrafe, J. et al. Cavity electro-optics in thin-film lithium niobate for efficient microwave-to-optical transduction. Optica 7, 1714–1720 (2020).
Clerk, A. A., Lehnert, K. W., Bertet, P., Petta, J. R. & Nakamura, Y. Hybrid quantum systems with circuit quantum electrodynamics. Nat. Phys. 16, 257–267 (2020).
Wooten, E. L. et al. A review of lithium niobate modulators for fiber-optic communications systems. IEEE J. Sel. Topics Quantum Electron. 6, 69–82 (2000).
Pospieszalski, M. W., Weinreb, S., Norrod, R. D. & Harris, R. FETs and HEMTs at cryogenic temperatures—their properties and use in low-noise amplifiers. IEEE Trans. Microw. Theory Techn. 36, 552–560 (1988).
Duh, K. G. et al. Ultra-low-noise cryogenic high-electron-mobility transistors. IEEE Trans. Electron Devices 35, 249–256 (1988).
Weis, S. et al. Optomechanically induced transparency. Science 330, 1520–1523 (2010).
Zhou, X. et al. Slowing, advancing and switching of microwave signals using circuit nanoelectromechanics. Nat. Phys. 9, 179–184 (2013).
Safavi-Naeini, A. H. et al. Electromagnetically induced transparency and slow light with optomechanics. Nature 472, 69–73 (2011).
Teufel, J. D. et al. Circuit cavity electromechanics in the strong-coupling regime. Nature 471, 204–208 (2011).
Wang, C. et al. Integrated lithium niobate electro-optic modulators operating at CMOS-compatible voltages. Nature 562, 101–104 (2018).
He, Y. et al. Self-starting bi-chromatic LiNbO3 soliton microcomb. Optica 6, 1138–1144 (2019).
Thiele, F. et al. Cryogenic electro-optic polarisation conversion in titanium in-diffused lithium niobate waveguides. Opt. Express 28, 28961–28968 (2020).
Chakraborty, U. et al. Cryogenic operation of silicon photonic modulators based on the DC Kerr effect. Optica 7, 1385–1390 (2020).
Abel, S. et al. Large Pockels effect in micro- and nanostructured barium titanate integrated on silicon. Nat. Mater. 18, 42–47 (2019).
Eltes, F. et al. An integrated optical modulator operating at cryogenic temperatures. Nat. Mater. 19, 1164–1168 (2020).
Braginski, A. I. Superconductor electronics: status and outlook. J. Supercond. Nov. Magn. 32, 23–44 (2019).
Macklin, C. et al. A near–quantum-limited Josephson traveling-wave parametric amplifier. Science 350, 307–310 (2015).
Siddiqi, I. et al. RF-driven Josephson bifurcation amplifier for quantum measurement. Phys. Rev. Lett. 93, 207002 (2004).
Clerk, A. A., Devoret, M. H., Girvin, S. M., Marquardt, F. & Schoelkopf, R. J. Introduction to quantum noise, measurement, and amplification. Rev. Mod. Phys. 82, 1155–1208 (2010).
Herzog, C., Poberaj, G. & Günter, P. Electro-optic behavior of lithium niobate at cryogenic temperatures. Opt. Commun. 281, 793–796 (2008).
Morse, J. D. et al. Characterization of lithium niobate electro-optic modulators at cryogenic temperatures. Proc. SPIE Design, Simulation, and Fabrication of Optoelectronic Devices and Circuits 2150, 283–291 (1994).
McConaghy, C., Lowry, M., Becker, R. & Kincaid, B. The performance of pigtailed annealed proton exchange LiNbO3 modulators at cryogenic temperatures. IEEE Photon. Technol. Lett. 8, 1480–1482 (1996).
Yoshida, K., Kanda, Y. & Kohjiro, S. A traveling-wave-type LiNbO3 optical modulator with superconducting electrodes. IEEE Trans. Microw. Theory Techn. 47, 1201–1205 (1999).
How to measure BER (Keysight Technologies, 2018).
Teufel, J. D. et al. Sideband cooling of micromechanical motion to the quantum ground state. Nature 475, 359–363 (2011).
Wollman, E. E. et al. Quantum squeezing of motion in a mechanical resonator. Science 349, 952–955 (2015).
Ockeloen-Korppi, C. et al. Stabilized entanglement of massive mechanical oscillators. Nature 556, 478–482 (2018).
Bernier, N. R. et al. Nonreciprocal reconfigurable microwave optomechanical circuit. Nat. Commun. 8, 604 (2017).
Tóth, L. D., Bernier, N. R., Nunnenkamp, A., Feofanov, A. K. & Kippenberg, T. J. A dissipative quantum reservoir for microwave light using a mechanical oscillator. Nat. Phys. 13, 787–793 (2017).
Aspelmeyer, M., Kippenberg, T. J. & Marquardt, F. Cavity optomechanics. Rev. Mod. Phys. 86, 1391 (2014).
Bernier, N. R. Multimode microwave circuit optomechanics as a platform to study coupled quantum harmonic oscillators. Dissertation, EPFL (2018).
Marquardt, F., Harris, J. & Girvin, S. M. Dynamical multistability induced by radiation pressure in high-finesse micromechanical optical cavities. Phys. Rev. Lett. 96, 103901 (2006).
Carmon, T., Rokhsari, H., Yang, L., Kippenberg, T. J. & Vahala, K. J. Temporal behavior of radiation-pressure-induced vibrations of an optical microcavity phonon mode. Phys. Rev. Lett. 94, 223902 (2005).
Cha, E. et al. A 300-μw cryogenic HEMT LNA for quantum computing. 2020 IEEE/MTT-S International Microwave Symposium (IMS) 1299–1302 (2020).
Cha, E. et al. InP HEMTs for sub-mW cryogenic low-noise amplifiers. IEEE Electron Device Lett. 41, 1005–1008 (2020).
Wong, W.-T., Hosseini, M., Rücker, H. & Bardin, J. C. A 1 mW cryogenic LNA exploiting optimized SiGe HBTs to achieve an average noise temperature of 3.2 K from 4–8 GHz. 2020 IEEE/MTT-S International Microwave Symposium (IMS) 181–184 (2020).
We thank N. J. Engelsen for thorough reading of the manuscript. This work was supported by the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 732894 (FET Proactive HOT), and by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 835329). This work was supported by funding from the Swiss National Science Foundation under grant agreement NCCR-QSIT:51NF40_185902 and Sinergia grant no. 186364 (QuantEOM). The circuit electromechanical device was fabricated in the Center of MicroNanoTechnology (CMi) at EPFL.
The authors declare no competing interests.
Peer review information Nature Electronics thanks the anonymous reviewers for their contribution to the peer review of this work.
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a, Propagation of the DUT signal through the system. b, Power spectral density of the HEMT output. c, Power spectral density of the optical heterodyne detector.
Pre-amplifier gain, GPA ~102, and transduction gain, G. The equivalent added noise referred to the input after the second amplification stage is ~(GPAG)−1.
a, Relative temperature difference between PM box and heat exchanger, on 800 mK flange during a cooldown. The gray datapoints correspond to specific periods of pulse precooling and mixture condensation, where the temperature is unstable. b, Measurement of heating due to optical dissipation when the phase modulator is mounted on the 800 mK flange. c, Measurement of heating using a calibrated resistive heater mounted on the 800 mK flange.
a, Experimental setup and schematic signal flow. A noise source thermalized at temperature T feeds the HEMT with Johnson noise. The measured power spectral density is proportional to the noise from the source plus the HEMT added noise. The noise source is a thermally isolated copper block containing a cryogenic resistive heater, a thermometer, and a 50Ω load. The noise source is connected to a 12 GHz low-pass filter. b, The added noise of the HEMT versus frequency. Inset: An example of the measured power spectral density at 6 GHz vs. T. The dashed line is to a fit Eq. (11).
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Youssefi, A., Shomroni, I., Joshi, Y.J. et al. A cryogenic electro-optic interconnect for superconducting devices. Nat Electron 4, 326–332 (2021). https://doi.org/10.1038/s41928-021-00570-4
Nature Electronics (2021)