TY - JOUR AB - 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. AU - Sahu, Rishabh AU - Qiu, Liu AU - Hease, William J AU - Arnold, Georg M AU - Minoguchi, Y. AU - Rabl, P. AU - Fink, Johannes M ID - 13106 IS - 6646 JF - Science KW - Multidisciplinary SN - 0036-8075 TI - Entangling microwaves with light VL - 380 ER - TY - JOUR AB - 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. AU - Qiu, Liu AU - Sahu, Rishabh AU - Hease, William J AU - Arnold, Georg M AU - Fink, Johannes M ID - 13200 JF - Nature Communications TI - Coherent optical control of a superconducting microwave cavity via electro-optical dynamical back-action VL - 14 ER - TY - CONF AB - 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. AU - Sahu, Rishabh AU - Qiu, Liu AU - Hease, William J AU - Arnold, Georg M AU - Minoguchi, Yuri AU - Rabl, Peter AU - Fink, Johannes M ID - 14872 SN - 9781957171296 T2 - Frontiers in Optics + Laser Science 2023 TI - Entangling microwaves and telecom wavelength light ER - TY - CONF AB - 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. AU - Sahu, Rishabh AU - Hease, William J AU - Rueda Sanchez, Alfredo R AU - Arnold, Georg M AU - Qiu, Liu AU - Fink, Johannes M ID - 12088 SN - 9781557528209 T2 - Conference on Lasers and Electro-Optics TI - Realizing a quantum-enabled interconnect between microwave and telecom light ER - TY - JOUR AB - 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. AU - Sahu, Rishabh AU - Hease, William J AU - Rueda Sanchez, Alfredo R AU - Arnold, Georg M AU - Qiu, Liu AU - Fink, Johannes M ID - 10924 JF - Nature Communications TI - Quantum-enabled operation of a microwave-optical interface VL - 13 ER - TY - JOUR AB - 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 Vπ 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. AU - Arnold, Georg M AU - Wulf, Matthias AU - Barzanjeh, Shabir AU - Redchenko, Elena AU - Rueda Sanchez, Alfredo R AU - Hease, William J AU - Hassani, Farid AU - Fink, Johannes M ID - 8529 JF - Nature Communications KW - General Biochemistry KW - Genetics and Molecular Biology KW - General Physics and Astronomy KW - General Chemistry SN - 2041-1723 TI - Converting microwave and telecom photons with a silicon photonic nanomechanical interface VL - 11 ER - TY - GEN AB - 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. AU - Arnold, Georg M AU - Wulf, Matthias AU - Barzanjeh, Shabir AU - Redchenko, Elena AU - Rueda Sanchez, Alfredo R AU - Hease, William J AU - Hassani, Farid AU - Fink, Johannes M ID - 13056 TI - Converting microwave and telecom photons with a silicon photonic nanomechanical interface ER - TY - JOUR AB - 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. AU - Hease, William J AU - Rueda Sanchez, Alfredo R AU - Sahu, Rishabh AU - Wulf, Matthias AU - Arnold, Georg M AU - Schwefel, Harald G.L. AU - Fink, Johannes M ID - 9114 IS - 2 JF - PRX Quantum SN - 2691-3399 TI - Bidirectional electro-optic wavelength conversion in the quantum ground state VL - 1 ER - TY - GEN AB - 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. AU - Hease, William J AU - Rueda Sanchez, Alfredo R AU - Sahu, Rishabh AU - Wulf, Matthias AU - Arnold, Georg M AU - Schwefel, Harald AU - Fink, Johannes M ID - 13071 TI - Bidirectional electro-optic wavelength conversion in the quantum ground state ER - TY - JOUR AB - Mechanical systems facilitate the development of a hybrid quantum technology comprising electrical, optical, atomic and acoustic degrees of freedom1, and entanglement is essential to realize quantum-enabled devices. Continuous-variable entangled fields—known as Einstein–Podolsky–Rosen (EPR) states—are spatially separated two-mode squeezed states that can be used for quantum teleportation and quantum communication2. In the optical domain, EPR states are typically generated using nondegenerate optical amplifiers3, and at microwave frequencies Josephson circuits can serve as a nonlinear medium4,5,6. An outstanding goal is to deterministically generate and distribute entangled states with a mechanical oscillator, which requires a carefully arranged balance between excitation, cooling and dissipation in an ultralow noise environment. Here we observe stationary emission of path-entangled microwave radiation from a parametrically driven 30-micrometre-long silicon nanostring oscillator, squeezing the joint field operators of two thermal modes by 3.40 decibels below the vacuum level. The motion of this micromechanical system correlates up to 50 photons per second per hertz, giving rise to a quantum discord that is robust with respect to microwave noise7. Such generalized quantum correlations of separable states are important for quantum-enhanced detection8 and provide direct evidence of the non-classical nature of the mechanical oscillator without directly measuring its state9. This noninvasive measurement scheme allows to infer information about otherwise inaccessible objects, with potential implications for sensing, open-system dynamics and fundamental tests of quantum gravity. In the future, similar on-chip devices could be used to entangle subsystems on very different energy scales, such as microwave and optical photons. AU - Barzanjeh, Shabir AU - Redchenko, Elena AU - Peruzzo, Matilda AU - Wulf, Matthias AU - Lewis, Dylan AU - Arnold, Georg M AU - Fink, Johannes M ID - 6609 JF - Nature TI - Stationary entangled radiation from micromechanical motion VL - 570 ER -