9 research outputs found
Robust Charge-based Qubit Encoding
We propose a simple encoding of charge-based quantum dot qubits which
protects against fluctuating electric fields by charge symmetry. We analyse the
reduction of coupling to noise due to nearby charge traps and present single
qubit gates. The relative advantage of the encoding increases with lower charge
trap density.Comment: 6 Pages, 7 Figures. Published Versio
Quantum optomechanical measurement of the phonon number dynamics of a mesoscopic mechanical resonator
We analyse the generic case of an optomechanical system with coupling quadratic in the mechanical displacement. Using the stochastic master equation formalism, we establish constraints necessary to observe quantum jumps in the phonon number
Phonon number quantum jumps in an optomechanical system
We analyse the generic case of an optomechanical system with coupling quadratic in the mechanical displacement. Using the stochastic master equation formalism, we establish constraints necessary to observe quantum jumps in the phonon number
Insights into long-range, high-temperature quantum coherence in quantum dot networks from photosynthesis
Two-dimensional femtosecond spectroscopic studies have suggested some photosynthetic light harvesting protein complexes (LHCs) utilise quantum searches to improve the efficiency of exciton transport through networks of chromophores to chemical reaction centers (RCs) [1-4]. This has stimulated theoretical work in the quantum chemistry and quantum information communities, with particular focus on the so-called Frenkel Hamiltonian, which models chromophores as quantum dots. Findings indicate that high-efficiency exciton transport in individual LHCs is achieved via an interplay between excitonic quantum coherence, resonant vibrations in the surrounding protein matrix, and thermal decoherence [5-13]
Introgression of crop alleles into wild or weedy populations
The evolutionary significance of introgression has been discussed for decades. Questions about potential impacts of transgene flow into wild and weedy populations brought renewed attention to the introgression of crop alleles into those populations. In the last past two decades, the field has advanced with considerable descriptive, experimental, and theoretical activity on the dynamics of crop gene introgression and its consequences. As illustrated by five case studies employing an array of different approaches, introgression of crop alleles has occurred for a wide array of species, sometimes without significant consequence, but on occasion leading to the evolution of increased weediness. A new theoretical context has emerged for analyzing empirical data, identifying factors that influence introgression, and predicting introgression’s progress. With emerging molecular techniques and analyses, research on crop allele introgression into wild and weedy populations is positioned to make contributions to both transgene risk assessment and reticulate evolution
Historical ecology on Sandoy, Faroe Islands: palaeoenvironmental and archaeological perspectives
We present palaeoenvironmental, geomorphological, archaeological, and place-name data which allow a holistic assessment of the history of landscape change on Sandoy, Faroe Islands, especially in terms of the changes that occurred in response to the colonization of the island by humans. In contrast to other situations in the North Atlantic region, there is considerable continuity in the patterns and processes of landscape evolution across the initial settlement horizon. Many of the characteristic features of postsettlement North Atlantic landscapes - absence of trees, widespread blanket mires, high rates of soil erosion - were already in place when the first people arrived. Although human impact on Sandoy appears to have been light, conversely, the unusual environment forced major alterations of the subsistence economy imported by the colonists. Settlement-era archaeological records suggest that, from the start, patterns of resource use differed substantially from the regional norm, and these differences became amplified over time as the Faroese economy created a locally sustainable cultural landscape