Krishna C. Balram
University of Bristol
PiezoelectricityOpticsPhysicsFabricationPhotonMaterials sciencePhotonicsPhotodetectorPhononOptomechanicsComputer scienceMicrowaveOptoelectronicsGallium arsenideQuantum information scienceSiliconGermaniumWavelengthRadio frequencyResonator
65Publications
15H-index
995Citations
Publications 60
Newest
#1Joe Smith (UoB: University of Bristol)H-Index: 9
#2Jorge Monroy-RuzH-Index: 4
Last. Krishna C. BalramH-Index: 15
view all 5 authors...
At visible wavelengths, photonic components could be designed at micron-scales to synchronously control time-critical systems. However, compatible photonics platforms have low refractive index contrasts, and so gratings must be physically large for energy to be efficiently refracted. We develop two ideas to address this problem: a second-order grating that sums multiple optical modes to increase its intensity output, and an embedded metal grating that significantly enhances the attainable refrac...
#1Stefano Valle (UoB: University of Bristol)H-Index: 8
#2Krishna C. Balram (UoB: University of Bristol)H-Index: 15
Suspended high-overtone bulk acoustic wave resonators (HBARs) can serve as a viable optomechanical platform for efficient transduction of signals from the microwave to the optical frequency domain. In contrast to 1D nanobeam optomechanical crystals, HBARs benefit from very high RF to phonon injection efficiency (\eta_{PIE}\approx) and low optical pump induced heating at cryogenic temperatures. By building small mode volume optical cavities around these devices, one can in principle achieve op...
Most of the architectural research on photonic implementations of measurement-based quantum computing (MBQC) has focused on the quantum resources involved in the problem with the implicit assumption that these will provide the main constraints on system scaling. However, the `flying-qubit' architecture of photonic MBQC requires specific timing constraints that need to be met by the classical control system. This classical control includes, for example: the amplification of the signals from singl...
#1Krishna C. Balram (UoB: University of Bristol)H-Index: 15
#2Kartik Srinivasan (NIST: National Institute of Standards and Technology)H-Index: 63
Piezoelectric optomechanical platforms represent one of the most promising routes towards achieving quantum transduction of photons between the microwave and optical frequency domains. However, there are significant challenges to achieving near-unity transduction efficiency. We discuss such factors in the context of the two main approaches being pursued for high efficiency transduction. The first approach uses one-dimensional nanobeam optomechanical crystals excited by interdigitated transducers...
#1Jorge Monroy-Ruz (UoB: University of Bristol)H-Index: 4
Last. Krishna C. Balram (UoB: University of Bristol)H-Index: 15
view all 5 authors...
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#1Stefano Valle (UoB: University of Bristol)H-Index: 8
#2Krishna C. Balram (UoB: University of Bristol)H-Index: 15
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#1Ankur KhuranaH-Index: 1
#2Pisu Jiang (UoB: University of Bristol)H-Index: 4
Last. Krishna C. Balram (UoB: University of Bristol)H-Index: 15
view all 3 authors...
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#1Biswarup Guha (NIST: National Institute of Standards and Technology)H-Index: 1
#2Marcelo Wu (NIST: National Institute of Standards and Technology)H-Index: 9
Last. Kartik Srinivasan (NIST: National Institute of Standards and Technology)H-Index: 63
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We demonstrate three methods for microwave actuation of GaAs nanobeam piezo-optomechanical resonators, based on interdigitated transducers, piezoelectric resonators, and micro-antenna structures. Potential applications of these devices range from bi-directional microwave-to-optical conversion to optomechanical thermometry.
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#1Joe Smith (UoB: University of Bristol)H-Index: 9
#2Chloe Clear (UoB: University of Bristol)H-Index: 1
Last. John Rarity (UoB: University of Bristol)H-Index: 75
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Solid-state atomlike systems have great promise for linear optic quantum computing and quantum communication but are burdened by phonon sidebands and broadening due to surface charges. Nevertheless, coupling to a small-mode-volume cavity would allow high rates of extraction from even highly dephased emitters. We consider the nitrogen-vacancy center in diamond, a system understood to have a poor quantum optics interface with highly distinguishable photons, and design a silicon nitride cavity that...
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#1Joe SmithH-Index: 9
#2Chloe ClearH-Index: 1
Last. John RarityH-Index: 75
view all 5 authors...
Solid state atom-like systems have great promise for building quantum networks at scale but are burdened by phonon sidebands and broadening due to surface charges. Nevertheless, coupling to a small mode volume cavity would allow high rates of extraction from even highly dephased emitters. We consider the nitrogen vacancy centre in diamond, a system understood to have a poor quantum optics interface with highly distinguishable photons, and design a silicon nitride cavity that allows 99 % efficien...
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