Impact of g-factors and valleys on spin qubits in a silicon double quantum dot

We define single electron spin qubits in a silicon MOS double quantum dot system. By mapping the qubit resonance frequency as a function of gate-induced electric field, the spectrum reveals an anticrossing that is consistent with an inter-valley spin-orbit coupling. We fit the data from which we extract an inter-valley coupling strength of 43 MHz. In addition, we observe a narrow resonance near the primary qubit resonance when we operate the device in the (1,1) charge configuration. The experimental data is consistent with a simulation involving two weakly exchanged-coupled spins with a g-factor difference of 1 MHz, of the same order as the Rabi frequency. We conclude that the narrow resonance is the result of driven transitions between the T- and T+ triplet states, using an ESR signal of frequency located halfway between the resonance frequencies of the two individual spins. The findings presented here offer an alternative method of implementing two-qubit gates, of relevance to the operation of larger scale spin qubit systems

What are the important thresholds and relationships to inform the management of COTS? Draft report, 30 June 2014

[Extract] The crown-of-thorns seastar (COTS), Acanthaster planci, is one of the main contributors to declines in coral cover on the Great Barrier Reef (GBR), and remains one of the major acute disturbances on coral reefs throughout much of the Indo-Pacific. The aim of this project is to investigate important ecological thresholds and relationships to inform the management of COTS. To do this we use a range of modelling methods as well as analyses of all available empirical data. Data from the management program removals of COTS provide near-real-time CPUE (Catch-Per-Unit-Effort) data that can be used to inform management

Electrospun amplified fiber optics

A lot of research is focused on all-optical signal processing, aiming to obtain effective alternatives to existing data transmission platforms. Amplification of light in fiber optics, such as in Erbium-doped fiber amplifiers, is especially important for an efficient signal transmission. However, the complex fabrication methods, involving high-temperature processes performed in highly pure environment, slow down the fabrication and make amplified components expensive with respect to an ideal, high-throughput and room temperature production. Here, we report on near infrared polymer fiber amplifiers, working over a band of about 20 nm. The fibers are cheap, spun with a process entirely carried out at room temperature, and show amplified spontaneous emission with good gain coefficients as well as low optical losses (a few cm^-1). The amplification process is favoured by the high fiber quality and low self-absorption. The found performance metrics promise to be suitable for short-distance operation, and the large variety of commercially-available doping dyes might allow for effective multi-wavelength operation by electrospun amplified fiber optics.Comment: 27 pages, 8 figure

Finding and treating gaucher disease type 1 - The role of the haematologist

Gaucher disease (GD) type 1 is the most common lysosomal storage disease and the most common genetic disorder among Ashkenazi Jews. The majority of patients with GD present with unexplained splenomegaly and/or thrombocytopenia, and the disorder often affects children; consequently, haematologists and paediatricians are ideally placed to diagnose this condition. Prompt management of GD type 1 using enzyme-replacement therapy or substrate reduction therapy can reduce the risk of developing long-term GD complications and reverse many of the initial signs/symptoms, thereby improving both quality and duration of life. Treatment is most effective when initiated early; consequently, a prompt diagnosis is essential. Despite this, the average time to diagnosis following the onset of clinical symptoms is 4 years. Reasons for the delay include the heterogeneous nature of the disease, together with a lack of awareness of rare haematological disorders and the benefits of early treatment. Indeed, studies show that only 20% of haematologists consider GD type 1 in their differential diagnosis for patients presenting with splenomegaly and/or thrombocytopenia. To help raise awareness of GD, reduce the diagnostic delay and prevent unnecessary tissue biopsies, simple diagnostic algorithms and screening tools have been developed and validated, both in adults and in children

FPGA-based real-time data processing for accelerating reconstruction at LHCb

In run-3, beginning in 2022, the LHCb software trigger will start reconstructing events at the LHC average crossing rate of 30 MHz. Within the upgraded DAQ system, LHCb established a testbed for new heterogeneous computing solutions for real-time event reconstruction, in view of future runs at even higher luminosities. One such solution is a highly-parallelized custom tracking processor ("Artificial Retina"), implemented in state of the art FPGA devices connected by fast serial links. We describe the status of a realistic prototype for the reconstruction of pixel tracking detectors that will run on real data during run-3

Resonant tunnelling features in the transport spectroscopy of quantum dots

We present a review of features due to resonant tunnelling in transport spectroscopy experiments on quantum dots and single donors. The review covers features attributable to intrinsic properties of the dot as well as extrinsic effects, with a focus on the most common operating conditions. We describe several phenomena that can lead to apparently identical signatures in a bias spectroscopy measurement, with the aim of providing experimental methods to distinguish between their different physical origins. The correct classification of the resonant tunnelling features is an essential requirement to understand the details of the confining potential or predict the performance of the dot for quantum information processing.Comment: 18 pages, 7 figures. Short review article submitted to Nanotechnology, special issue on 'Quantum Science and Technology at the Nanoscale

Manejo da cultura do algodão com resultados de pesquisa em Goiás.

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