@inproceedings{14872,
  abstract     = {We entangled microwave and optical photons for the first time as verified by a measured two-mode vacuum squeezing of 0.7 dB. This electro-optic entanglement is the key resource needed to connect cryogenic quantum circuits.},
  author       = {Sahu, Rishabh and Qiu, Liu and Hease, William J and Arnold, Georg M and Minoguchi, Yuri and Rabl, Peter and Fink, Johannes M},
  booktitle    = {Frontiers in Optics + Laser Science 2023},
  isbn         = {9781957171296},
  location     = {Tacoma, WA, United States},
  publisher    = {Optica Publishing Group},
  title        = {{Entangling microwaves and telecom wavelength light}},
  doi          = {10.1364/ls.2023.lm1f.3},
  year         = {2023},
}

@phdthesis{13106,
  abstract     = {Quantum entanglement is a key resource in currently developed quantum technologies. Sharing this fragile property between superconducting microwave circuits and optical or atomic systems would enable new functionalities, but this has been hindered by an energy scale mismatch of >104 and the resulting mutually imposed loss and noise. In this work, we created and verified entanglement between microwave and optical fields in a millikelvin environment. Using an optically pulsed superconducting electro-optical device, we show entanglement between propagating microwave and optical fields in the continuous variable domain. This achievement not only paves the way for entanglement between superconducting circuits and telecom wavelength light, but also has wide-ranging implications for hybrid quantum networks in the context of modularization, scaling, sensing, and cross-platform verification.},
  author       = {Sahu, Rishabh and Qiu, Liu and Hease, William J and Arnold, Georg M and Minoguchi, Y. and Rabl, P. and Fink, Johannes M},
  issn         = {1095-9203},
  keywords     = {Multidisciplinary},
  pages        = {718--721},
  publisher    = {American Association for the Advancement of Science},
  title        = {{Entangling microwaves with light}},
  doi          = {10.1126/science.adg3812},
  volume       = {380},
  year         = {2023},
}

@article{13200,
  abstract     = {Recent quantum technologies have established precise quantum control of various microscopic systems using electromagnetic waves. Interfaces based on cryogenic cavity electro-optic systems are particularly promising, due to the direct interaction between microwave and optical fields in the quantum regime. Quantum optical control of superconducting microwave circuits has been precluded so far due to the weak electro-optical coupling as well as quasi-particles induced by the pump laser. Here we report the coherent control of a superconducting microwave cavity using laser pulses in a multimode electro-optical device at millikelvin temperature with near-unity cooperativity. Both the stationary and instantaneous responses of the microwave and optical modes comply with the coherent electro-optical interaction, and reveal only minuscule amount of excess back-action with an unanticipated time delay. Our demonstration enables wide ranges of applications beyond quantum transductions, from squeezing and quantum non-demolition measurements of microwave fields, to entanglement generation and hybrid quantum networks.},
  author       = {Qiu, Liu and Sahu, Rishabh and Hease, William J and Arnold, Georg M and Fink, Johannes M},
  issn         = {2041-1723},
  journal      = {Nature Communications},
  publisher    = {Nature Research},
  title        = {{Coherent optical control of a superconducting microwave cavity via electro-optical dynamical back-action}},
  doi          = {10.1038/s41467-023-39493-3},
  volume       = {14},
  year         = {2023},
}

@article{10924,
  abstract     = {Solid-state microwave systems offer strong interactions for fast quantum logic and sensing but photons at telecom wavelength are the ideal choice for high-density low-loss quantum interconnects. A general-purpose interface that can make use of single photon effects requires < 1 input noise quanta, which has remained elusive due to either low efficiency or pump induced heating. Here we demonstrate coherent electro-optic modulation on nanosecond-timescales with only 0.16+0.02−0.01 microwave input noise photons with a total bidirectional transduction efficiency of 8.7% (or up to 15% with 0.41+0.02−0.02), as required for near-term heralded quantum network protocols. The use of short and high-power optical pump pulses also enables near-unity cooperativity of the electro-optic interaction leading to an internal pure conversion efficiency of up to 99.5%. Together with the low mode occupancy this provides evidence for electro-optic laser cooling and vacuum amplification as predicted a decade ago.},
  author       = {Sahu, Rishabh and Hease, William J and Rueda Sanchez, Alfredo R and Arnold, Georg M and Qiu, Liu and Fink, Johannes M},
  issn         = {20411723},
  journal      = {Nature Communications},
  publisher    = {Springer Nature},
  title        = {{Quantum-enabled operation of a microwave-optical interface}},
  doi          = {10.1038/s41467-022-28924-2},
  volume       = {13},
  year         = {2022},
}

@inproceedings{12088,
  abstract     = {We present a quantum-enabled microwave-telecom interface with bidirectional conversion efficiencies up to 15% and added input noise quanta as low as 0.16. Moreover, we observe evidence for electro-optic laser cooling and vacuum amplification.},
  author       = {Sahu, Rishabh and Hease, William J and Rueda Sanchez, Alfredo R and Arnold, Georg M and Qiu, Liu and Fink, Johannes M},
  booktitle    = {Conference on Lasers and Electro-Optics},
  isbn         = {9781557528209},
  location     = {San Jose, CA, United States},
  publisher    = {Optica Publishing Group},
  title        = {{Realizing a quantum-enabled interconnect between microwave and telecom light}},
  doi          = {10.1364/CLEO_QELS.2022.FW4D.4},
  year         = {2022},
}

@article{8529,
  abstract     = {Practical quantum networks require low-loss and noise-resilient optical interconnects as well as non-Gaussian resources for entanglement distillation and distributed quantum computation. The latter could be provided by superconducting circuits but existing solutions to interface the microwave and optical domains lack either scalability or efficiency, and in most cases the conversion noise is not known. In this work we utilize the unique opportunities of silicon photonics, cavity optomechanics and superconducting circuits to demonstrate a fully integrated, coherent transducer interfacing the microwave X and the telecom S bands with a total (internal) bidirectional transduction efficiency of 1.2% (135%) at millikelvin temperatures. The coupling relies solely on the radiation pressure interaction mediated by the femtometer-scale motion of two silicon nanobeams reaching a <jats:italic>V</jats:italic><jats:sub><jats:italic>π</jats:italic></jats:sub> as low as 16 μV for sub-nanowatt pump powers. Without the associated optomechanical gain, we achieve a total (internal) pure conversion efficiency of up to 0.019% (1.6%), relevant for future noise-free operation on this qubit-compatible platform.},
  author       = {Arnold, Georg M and Wulf, Matthias and Barzanjeh, Shabir and Redchenko, Elena and Rueda Sanchez, Alfredo R and Hease, William J and Hassani, Farid and Fink, Johannes M},
  issn         = {2041-1723},
  journal      = {Nature Communications},
  keywords     = {General Biochemistry, Genetics and Molecular Biology, General Physics and Astronomy, General Chemistry},
  publisher    = {Springer Nature},
  title        = {{Converting microwave and telecom photons with a silicon photonic nanomechanical interface}},
  doi          = {10.1038/s41467-020-18269-z},
  volume       = {11},
  year         = {2020},
}

@misc{13056,
  abstract     = {This datasets comprises all data shown in plots of the submitted article "Converting microwave and telecom photons with a silicon photonic nanomechanical interface". Additional raw data are available from the corresponding author on reasonable request.},
  author       = {Arnold, Georg M and Wulf, Matthias and Barzanjeh, Shabir and Redchenko, Elena and Rueda Sanchez, Alfredo R and Hease, William J and Hassani, Farid and Fink, Johannes M},
  publisher    = {Zenodo},
  title        = {{Converting microwave and telecom photons with a silicon photonic nanomechanical interface}},
  doi          = {10.5281/ZENODO.3961561},
  year         = {2020},
}

@misc{13071,
  abstract     = {This dataset comprises all data shown in the plots of the main part of the submitted article "Bidirectional Electro-Optic Wavelength Conversion in the Quantum Ground State". Additional raw data are available from the corresponding author on reasonable request.},
  author       = {Hease, William J and Rueda Sanchez, Alfredo R and Sahu, Rishabh and Wulf, Matthias and Arnold, Georg M and Schwefel, Harald and Fink, Johannes M},
  publisher    = {Zenodo},
  title        = {{Bidirectional electro-optic wavelength conversion in the quantum ground state}},
  doi          = {10.5281/ZENODO.4266025},
  year         = {2020},
}

@article{9114,
  abstract     = {Microwave photonics lends the advantages of fiber optics to electronic sensing and communication systems. In contrast to nonlinear optics, electro-optic devices so far require classical modulation fields whose variance is dominated by electronic or thermal noise rather than quantum fluctuations. Here we demonstrate bidirectional single-sideband conversion of X band microwave to C band telecom light with a microwave mode occupancy as low as 0.025 ± 0.005 and an added output noise of less than or equal to 0.074 photons. This is facilitated by radiative cooling and a triply resonant ultra-low-loss transducer operating at millikelvin temperatures. The high bandwidth of 10.7 MHz and total (internal) photon conversion
efficiency of 0.03% (0.67%) combined with the extremely slow heating rate of 1.1 added output noise photons per second for the highest available pump power of 1.48 mW puts near-unity efficiency pulsed quantum transduction within reach. Together with the non-Gaussian resources of superconducting qubits this might provide the practical foundation to extend the range and scope of current quantum networks in analogy to electrical repeaters in classical fiber optic communication.},
  author       = {Hease, William J and Rueda Sanchez, Alfredo R and Sahu, Rishabh and Wulf, Matthias and Arnold, Georg M and Schwefel, Harald G.L. and Fink, Johannes M},
  issn         = {2691-3399},
  journal      = {PRX Quantum},
  number       = {2},
  publisher    = {American Physical Society},
  title        = {{Bidirectional electro-optic wavelength conversion in the quantum ground state}},
  doi          = {10.1103/prxquantum.1.020315},
  volume       = {1},
  year         = {2020},
}

@article{7156,
  abstract     = {We propose an efficient microwave-photonic modulator as a resource for stationary entangled microwave-optical fields and develop the theory for deterministic entanglement generation and quantum state transfer in multi-resonant electro-optic systems. The device is based on a single crystal whispering gallery mode resonator integrated into a 3D-microwave cavity. The specific design relies on a new combination of thin-film technology and conventional machining that is optimized for the lowest dissipation rates in the microwave, optical, and mechanical domains. We extract important device properties from finite-element simulations and predict continuous variable entanglement generation rates on the order of a Mebit/s for optical pump powers of only a few tens of microwatts. We compare the quantum state transfer fidelities of coherent, squeezed, and non-Gaussian cat states for both teleportation and direct conversion protocols under realistic conditions. Combining the unique capabilities of circuit quantum electrodynamics with the resilience of fiber optic communication could facilitate long-distance solid-state qubit networks, new methods for quantum signal synthesis, quantum key distribution, and quantum enhanced detection, as well as more power-efficient classical sensing and modulation.},
  author       = {Rueda Sanchez, Alfredo R and Hease, William J and Barzanjeh, Shabir and Fink, Johannes M},
  issn         = {2056-6387},
  journal      = {npj Quantum Information},
  publisher    = {Springer Nature},
  title        = {{Electro-optic entanglement source for microwave to telecom quantum state transfer}},
  doi          = {10.1038/s41534-019-0220-5},
  volume       = {5},
  year         = {2019},
}