scholarly journals Demonstration of non-Markovian process characterisation and control on a quantum processor

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
G. A. L. White ◽  
C. D. Hill ◽  
F. A. Pollock ◽  
L. C. L. Hollenberg ◽  
K. Modi
Keyword(s):  
Quantum Control ◽  
Scale Up ◽  
Coherence Time ◽  
Error Type ◽  
Markovian Dynamics ◽  
Quantum Device ◽  
Significant Step ◽  
Quantum Technology ◽  
And Control ◽  
Device Operation

AbstractIn the scale-up of quantum computers, the framework underpinning fault-tolerance generally relies on the strong assumption that environmental noise affecting qubit logic is uncorrelated (Markovian). However, as physical devices progress well into the complex multi-qubit regime, attention is turning to understanding the appearance and mitigation of correlated — or non-Markovian — noise, which poses a serious challenge to the progression of quantum technology. This error type has previously remained elusive to characterisation techniques. Here, we develop a framework for characterising non-Markovian dynamics in quantum systems and experimentally test it on multi-qubit superconducting quantum devices. Where noisy processes cannot be accounted for using standard Markovian techniques, our reconstruction predicts the behaviour of the devices with an infidelity of 10−3. Our results show this characterisation technique leads to superior quantum control and extension of coherence time by effective decoupling from the non-Markovian environment. This framework, validated by our results, is applicable to any controlled quantum device and offers a significant step towards optimal device operation and noise reduction.

scholarly journals Characterization and control of open quantum systems beyond quantum noise spectroscopy

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Akram Youssry ◽  
Gerardo A. Paz-Silva ◽  
Christopher Ferrie
Keyword(s):  
Quantum Control ◽  
Performance Metrics ◽  
Quantum Noise ◽  
Open Quantum Systems ◽  
Power Spectra ◽  
General Purpose ◽  
Noise Power ◽  
Noise Spectroscopy ◽  
Quantum Technology ◽  
And Control

AbstractThe ability to use quantum technology to achieve useful tasks, be they scientific or industry related, boils down to precise quantum control. In general it is difficult to assess a proposed solution due to the difficulties in characterizing the quantum system or device. These arise because of the impossibility to characterize certain components in situ, and are exacerbated by noise induced by the environment and active controls. Here, we present a general purpose characterization and control solution making use of a deep learning framework composed of quantum features. We provide the framework, sample datasets, trained models, and their performance metrics. In addition, we demonstrate how the trained model can be used to extract conventional indicators, such as noise power spectra.

scholarly journals Room-temperature control and electrical readout of individual nitrogen-vacancy nuclear spins

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Michal Gulka ◽  
Daniel Wirtitsch ◽  
Viktor Ivády ◽  
Jelle Vodnik ◽  
Jaroslav Hruby ◽  
...  
Keyword(s):  
Dipolar Interaction ◽  
Coherence Time ◽  
Wide Bandgap ◽  
Nitrogen Vacancy ◽  
Ambient Conditions ◽  
Nuclear Spins ◽  
Quantum Device ◽  
Nanoscale Electronics ◽  
Quantum Processor ◽  
Processor Unit

AbstractNuclear spins in semiconductors are leading candidates for future quantum technologies, including quantum computation, communication, and sensing. Nuclear spins in diamond are particularly attractive due to their long coherence time. With the nitrogen-vacancy (NV) centre, such nuclear qubits benefit from an auxiliary electronic qubit, which, at cryogenic temperatures, enables probabilistic entanglement mediated optically by photonic links. Here, we demonstrate a concept of a microelectronic quantum device at ambient conditions using diamond as wide bandgap semiconductor. The basic quantum processor unit – a single 14N nuclear spin coupled to the NV electron – is read photoelectrically and thus operates in a manner compatible with nanoscale electronics. The underlying theory provides the key ingredients for photoelectric quantum gate operations and readout of nuclear qubit registers. This demonstration is, therefore, a step towards diamond quantum devices with a readout area limited by inter-electrode distance rather than by the diffraction limit. Such scalability could enable the development of electronic quantum processors based on the dipolar interaction of spin-qubits placed at nanoscopic proximity.

scholarly journals Potential applications of halophilic microorganisms for biological treatment of industrial process brines contaminated with aromatics

2021 ◽  
Author(s):  
Thomas Mainka ◽  
David Weirathmüller ◽  
Christoph Herwig ◽  
Stefan Pflügl
Keyword(s):  
Wastewater Treatment ◽  
Process Monitoring ◽  
Industrial Wastewater ◽  
Continuous Process ◽  
Scale Up ◽  
Monitoring And Control ◽  
Saline Wastewater ◽  
Halophilic Microorganisms ◽  
Industrial Sectors ◽  
And Control

Abstract Saline wastewater contaminated with aromatic compounds can be frequently found in various industrial sectors. Those compounds need to be degraded before reuse of wastewater in other process steps or release to the environment. Halophiles have been reported to efficiently degrade aromatics, but their application to treat industrial wastewater is rare. Halophilic processes for industrial wastewater treatment need to satisfy certain requirements: a continuous process mode, low operational expenditures, suitable reactor systems and a monitoring and control strategy. The aim of this review is to provide an overview of halophilic microorganisms, principles of aromatic biodegradation, and sources of saline wastewater containing aromatics and other contaminants. Finally, process examples for halophilic wastewater treatment and potential process monitoring strategies are discussed. To further illustrate the significant potential of halophiles for saline wastewater treatment and to facilitate development of ready-to-implement processes, future research should focus on scale-up and innovative process monitoring and control strategies.

scholarly journals Electron shelving of a superconducting artificial atom

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nathanaël Cottet ◽  
Haonan Xiong ◽  
Long B. Nguyen ◽  
Yen-Hsiang Lin ◽  
Vladimir E. Manucharyan
Keyword(s):  
Quantum Electrodynamics ◽  
Optical Pumping ◽  
Radiative Lifetime ◽  
Resonant Cavity ◽  
Coherence Time ◽  
Fluorescence Signal ◽  
Circuit Quantum Electrodynamics ◽  
Artificial Atom ◽  
Cavity Modes ◽  
Quantum Technology

AbstractInterfacing long-lived qubits with propagating photons is a fundamental challenge in quantum technology. Cavity and circuit quantum electrodynamics (cQED) architectures rely on an off-resonant cavity, which blocks the qubit emission and enables a quantum non-demolition (QND) dispersive readout. However, no such buffer mode is necessary for controlling a large class of three-level systems that combine a metastable qubit transition with a bright cycling transition, using the electron shelving effect. Here we demonstrate shelving of a circuit atom, fluxonium, placed inside a microwave waveguide. With no cavity modes in the setup, the qubit coherence time exceeds 50 μs, and the cycling transition’s radiative lifetime is under 100 ns. By detecting a homodyne fluorescence signal from the cycling transition, we implement a QND readout of the qubit and account for readout errors using a minimal optical pumping model. Our result establishes a resource-efficient (cavityless) alternative to cQED for controlling superconducting qubits.

scholarly journals The Use of Granular Cyclopentanone as Alternative to Artificial Source of Carbon Dioxide in Improved Passive Outdoor Host Seeking Device (POHD)

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Stella T. Kessy ◽  
Bruno A. Nyundo ◽  
Ladslaus L. Mnyone ◽  
Issa N. Lyimo
Keyword(s):  
Electrical Power ◽  
Scale Up ◽  
Residual Activity ◽  
Yeast Fermentation ◽  
Power Sources ◽  
Host Seeking ◽  
Relative Attractiveness ◽  
Residual Malaria Transmission ◽  
Control Devices ◽  
And Control

Reliable sources of CO2 that are relatively cheap, obtainable, and easy to sustain are immediately required for scaling up of odor-baited mosquito surveillance and control devices. Several odor-baited devices are in the pipeline; however, their scale-up against residual malaria transmission, particularly in resource poor areas, is limited by the unavailability of reliable sources of CO2 and reliance on electrical power sources among other factors. We evaluated the use of granular cyclopentanone as an alternative to artificial or yeast fermentation-produced CO2 in passive outdoor host seeking device (POHD). Experiments were conducted against semifield reared An. arabiensis within the semifield system (SFS) at Ifakara Health Institute. Mosquitoes were tested against odor-baited POHDs augmented with yeast fermentation-produced CO2, granular cyclopentanone, attractive blends (Mbita or Ifakara), or their combinations. An insecticide, bendiocarb, was a killing agent used as a proxy for marking the mosquitoes visit the POHDs. Relative attractiveness of different treatment combinations was compared based on the proportion of dead mosquitoes that visited the POHD. The POHD augmented with granules of cyclopentanone alone was attractive to An. arabiensis as much as, or more than, POHDs augmented with yeast fermentation-produced CO2. The POHD baited with CO2 attracted more mosquitoes than those POHDs baited with synthetic blends alone; when these blends are combined with CO2, they attracted more mosquitoes than individual blends. More importantly, such POHDs baited with cyclopentanone attracted far greater proportion of mosquitoes than the POHD baited with either Mbita or Ifakara blend alone. The granular cyclopentanone strongly enhanced/potentiated the attractiveness of POHD baited with Mbita blends against mosquitoes compared to that of POHD baited with Ifakara blend. Moreover, the granular cyclopentanone retained its residual activity against An. arabiensis for up to 2 months after application particularly when used in combination with Mbita blend. In conclusion, this study demonstrates that cyclopentanone granules have the potential to substitute sources of CO2 in outdoor-based surveillance and control devices, thus warranting evaluation of such alternative under realistic field conditions.

An improved and robust scale-up process aided with identification and control of critical process impurities in darunavir ethanolate

2019 ◽  
Vol 46 (1) ◽  
pp. 267-281
Author(s):  
Sathyanarayana Girigani ◽  
Harnam Singh ◽  
Sankar Rao Kola ◽  
Vijayalaxmi Dayanand Yelmeli ◽  
Venu Gopal Regula ◽  
...  
Keyword(s):  
Scale Up ◽  
Darunavir Ethanolate ◽  
And Control ◽  
Critical Process

scholarly journals Moving from rhetoric to action: how Africa can use scientific evidence to halt the COVID-19 pandemic

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Olushayo Oluseun Olu ◽  
Joy Luba Lomole Waya ◽  
Sylvester Maleghemi ◽  
John Rumunu ◽  
David Ameh ◽  
...  
Keyword(s):  
Prevention And Control ◽  
Preventive Measures ◽  
Negative Impact ◽  
Control Strategies ◽  
Scientific Evidence ◽  
Scale Up ◽  
High Impact ◽  
The Social ◽  
And Control

Abstract The ongoing pandemic of the coronavirus disease 2019 has spread rapidly to all countries of the world. Africa is particularly predisposed to an escalation of the pandemic and its negative impact given its weak economy and health systems. In addition, inadequate access to the social determinants of health such as water and sanitation and socio-cultural attributes may constrain the implementation of critical preventive measures such as hand washing and social distancing on the continent. Given these facts, the continent needs to focus on targeted and high impact prevention and control strategies and interventions which could break the chain of transmission quickly. We conclude that the available body of scientific evidence on the coronavirus disease 2019 holds the key to the development of such strategies and interventions. Going forward, we recommend that the African research community should scale up research to provide scientific evidence for a better characterization of the epidemiology, transmission dynamics, prevention and control of the virus on the continent.

Scale-up of services and research priorities for diagnosis, management, and control of tuberculosis: a call to action

The Lancet ◽  
2010 ◽  
Vol 375 (9732) ◽  
pp. 2179-2191 ◽  
Author(s):  
Ben J Marais ◽  
Mario C Raviglione ◽  
Peter R Donald ◽  
Anthony D Harries ◽  
Afranio L Kritski ◽  
...  
Keyword(s):  
Scale Up ◽  
Research Priorities ◽  
Call To Action ◽  
And Control
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