@article{9815,
  abstract     = {The quantum bits (qubits) on which superconducting quantum computers are based have energy scales corresponding to photons with GHz frequencies. The energy of photons in the gigahertz domain is too low to allow transmission through the noisy room-temperature environment, where the signal would be lost in thermal noise. Optical photons, on the other hand, have much higher energies, and signals can be detected using highly efficient single-photon detectors. Transduction from microwave to optical frequencies is therefore a potential enabling technology for quantum devices. However, in such a device the optical pump can be a source of thermal noise and thus degrade the fidelity; the similarity of input microwave state to the output optical state. In order to investigate the magnitude of this effect we model the sub-Kelvin thermal behavior of an electro-optic transducer based on a lithium niobate whispering gallery mode resonator. We find that there is an optimum power level for a continuous pump, whilst pulsed operation of the pump increases the fidelity of the conversion.},
  author       = {Mobassem, Sonia and Lambert, Nicholas J. and Rueda Sanchez, Alfredo R and Fink, Johannes M and Leuchs, Gerd and Schwefel, Harald G.L.},
  issn         = {2058-9565},
  journal      = {Quantum Science and Technology},
  number       = {4},
  publisher    = {IOP Publishing},
  title        = {{Thermal noise in electro-optic devices at cryogenic temperatures}},
  doi          = {10.1088/2058-9565/ac0f36},
  volume       = {6},
  year         = {2021},
}

@article{8038,
  abstract     = {Microelectromechanical systems and integrated photonics provide the basis for many reliable and compact circuit elements in modern communication systems. Electro-opto-mechanical devices are currently one of the leading approaches to realize ultra-sensitive, low-loss transducers for an emerging quantum information technology. Here we present an on-chip microwave frequency converter based on a planar aluminum on silicon nitride platform that is compatible with slot-mode coupled photonic crystal cavities. We show efficient frequency conversion between two propagating microwave modes mediated by the radiation pressure interaction with a metalized dielectric nanobeam oscillator. We achieve bidirectional coherent conversion with a total device efficiency of up to ~60%, a dynamic range of 2 × 10^9 photons/s and an instantaneous bandwidth of up to 1.7 kHz. A high fidelity quantum state transfer would be possible if the drive dependent output noise of currently ~14 photons s^−1 Hz^−1 is further reduced. Such a silicon nitride based transducer is in situ reconfigurable and could be used for on-chip classical and quantum signal routing and filtering, both for microwave and hybrid microwave-optical applications.},
  author       = {Fink, Johannes M and Kalaee, M. and Norte, R. and Pitanti, A. and Painter, O.},
  issn         = {2058-9565},
  journal      = {Quantum Science and Technology},
  number       = {3},
  publisher    = {IOP Publishing},
  title        = {{Efficient microwave frequency conversion mediated by a photonics compatible silicon nitride nanobeam oscillator}},
  doi          = {10.1088/2058-9565/ab8dce},
  volume       = {5},
  year         = {2020},
}