Enabling investment for the transition to a low carbon economy: government policy to finance early stage green innovation

Rapid transformation to meet the Paris 1.5oC climate target requires greater attention to be given to the role of innovative low carbon early stage businesses and the public sector’s role in addressing finance gaps for longer horizon investment requirements. As entrepreneurs require different forms of finance as their businesses grow and move up the ‘finance escalator’, we explore the role of public sector support for grant, equity, debt and new forms of crowd funding finance. These funds can enable individual sustainability focussed businesses to access finance and encourage finance into new areas through having a demonstration effect. We conclude that a finance ecosystem approach is required that ensures complementary forms of finance for low carbon investment are connected at local, national and international scales, alongside support to build entrepreneurial skills and investment readiness. There is also a need for better evidence of the role of public sector support and where there is greatest impact on climate change

Exchange coupling between silicon donors: the crucial role of the central cell and mass anisotropy

Donors in silicon are now demonstrated as one of the leading candidates for implementing qubits and quantum information processing. Single qubit operations, measurements and long coherence times are firmly established, but progress on controlling two qubit interactions has been slower. One reason for this is that the inter donor exchange coupling has been predicted to oscillate with separation, making it hard to estimate in device designs. We present a multivalley effective mass theory of a donor pair in silicon, including both a central cell potential and the effective mass anisotropy intrinsic in the Si conduction band. We are able to accurately describe the single donor properties of valley-orbit coupling and the spatial extent of donor wave functions, highlighting the importance of fitting measured values of hyperfine coupling and the orbital energy of the $1s$ levels. Ours is a simple framework that can be applied flexibly to a range of experimental scenarios, but it is nonetheless able to provide fast and reliable predictions. We use it to estimate the exchange coupling between two donor electrons and we find a smoothing of its expected oscillations, and predict a monotonic dependence on separation if two donors are spaced precisely along the [100] direction.Comment: Published version. Corrected b and B values from previous versio

Surface code architecture for donors and dots in silicon with imprecise and nonuniform qubit couplings

A scaled quantum computer with donor spins in silicon would benefit from a viable semiconductor framework and a strong inherent decoupling of the qubits from the noisy environment. Coupling neighbouring spins via the natural exchange interaction according to current designs requires gate control structures with extremely small length scales. We present a silicon architecture where bismuth donors with long coherence times are coupled to electrons that can shuttle between adjacent quantum dots, thus relaxing the pitch requirements and allowing space between donors for classical control devices. An adiabatic SWAP operation within each donor/dot pair solves the scalability issues intrinsic to exchange-based two-qubit gates, as it does not rely on sub-nanometer precision in donor placement and is robust against noise in the control fields. We use this SWAP together with well established global microwave Rabi pulses and parallel electron shuttling to construct a surface code that needs minimal, feasible local control.Comment: Published version - more detailed discussions, robustness to dephasing pointed out additionall

Financing Cleantech SME innovation: setting an agenda

The need for a clear research and policy agenda to assist early stage Cleantech financing has never been greater. These businesses may hold important keys to unlocking vital globally game changing technologies to tackle climate change. The paper provides an overview of recent academic literature and proposes a research agenda for early stage Cleantech SME finance. With growing interest in how to support innovations that tackle the climate emergency, there is a need for evidence that can assist the private sector, civil society organizations and policymakers in finding more effective ways to encourage impact investing and other finance for early stage Cleantech SMEs. This research agenda will therefore contribute to sustainability transitions in key sectors and the development of a sustainable low carbon economy

Early stage investing in green SMEs: the case of the UK

How might a Green New Deal be applied to the early stage financing of Cleantechs? Amidst rising interest and adoption of Green New Deals in the US, the paper explores the need for more focused policy to address early stage long horizon financing of Cleantechs. We argue that insufficient focus has been applied to early stage investing into these types of innovative SMEs that could lower CO2 emissions across a range of sectors (including renewable energy, recycling, advanced manufacturing, transport and bio-science). Adopting a resource complementarity lens and borrowing from transaction cost theory, we illustrate and build theory through longitudinal UK case studies. These demonstrate how government policy can scale-up through international collaboration public-private, principally venture capital, cofinance to facilitate cleantech innovation with potentially game changing impacts on reducing CO2 emissions in order to meet the Paris 2015 Climate Change targets

Establishment of short rotation forage crops

Non-Peer ReviewedForages could provide annual crop producers with a cash hay crop as a viable option in rotation. However, traditional perennial forage crop species that are difficult to establish and left in for many years are not the best option for short rotations of forage (1-3 years) and annual crops. Short-lived grass species that establish quickly and produce more forage for one to three years would provide traditional crop producers with a cash crop that would fit in their crop rotation system. New annual crops have not been tested as companion crops for establishment of grasses with high seedling vigour. The objective of the project is to determine the establishment success (risk) and first year production of fast-establishing forage grasses as affected by soil zone, companion crop, and legume associate

Broadband Achromatic Phase Shifter for a Nulling Interferometer

Nulling interferometry is a technique for imaging exoplanets in which light from the parent star is suppressed using destructive interference. Light from the star is divided into two beams and a phase shift of radians is introduced into one of the beams. When the beams are recombined, they destructively interfere to produce a deep null. For monochromatic light, this is implemented by introducing an optical path difference (OPD) between the two beams equal to lambda/2, where lambda is the wavelength of the light. For broadband light, however, a different phase shift will be introduced at each wavelength and the two beams will not effectively null when recombined. Various techniques have been devised to introduce an achromatic phase shift a phase shift that is uniform across a particular bandwidth. One popular technique is to use a series of dispersive elements to introduce a wavelength-dependent optical path in one or both of the arms of the interferometer. By intelligently choosing the number, material and thickness of a series of glass plates, a nearly uniform, arbitrary phase shift can be introduced between two arms of an interferometer. There are several constraints that make choosing the number, type, and thickness of materials a difficult problem, such as the size of the bandwidth to be nulled. Several solutions have been found for bandwidths on the order of 20 to 30 percent (Delta(lambda)/lambda(sub c)) in the mid-infrared region. However, uniform phase shifts over a larger bandwidth in the visible regime between 480 to 960 nm (67 percent) remain difficult to obtain at the tolerances necessary for exoplanet detection. A configuration of 10 dispersive glass plates was developed to be used as an achromatic phase shifter in nulling interferometry. Five glass plates were placed in each arm of the interferometer and an additional vacuum distance was also included in the second arm of the interferometer. This configuration creates a phase shift of pi radians with an average error of 5.97 x 10(exp -8) radians and standard deviation of 3.07 x 10(exp -4) radians. To reduce ghost reflections and interference effects from neighboring elements, the glass plates are tilted such that the beam does not strike each plate at normal incidence. Reflections will therefore walk out of the system and not contribute to the intensity when the beams are recombined. Tilting the glass plates, however, introduces several other problems that must be mitigated: (1) the polarization of a beam changes when refracted at an interface at non-normal incidence; (2) the beam experiences lateral chromatic spread as it traverses multiple glass plates; (3) at each surface, wavelength- dependent intensity losses will occur due to reflection. For a fixed angle of incidence, each of these effects must be balanced between each arm of the interferometer in order to ensure a deep null. The solution was found using a nonlinear optimization routine that minimized an objective function relating phase shift, intensity difference, chromatic beam spread, and polarization difference to the desired parameters: glass plate material and thickness. In addition to providing a uniform, broadband phase shift, the configuration achieves an average difference in intensity transmission between the two arms of the interferometer of 0.016 percent with a standard deviation of 3.64 x 10(exp -4) percent, an average difference in polarization between the two arms of the interferometer of 5.47 x 10(exp -5) percent with a standard deviation of 1.57 x 10(exp -6) percent, and an average chromatic beam shift between the two arms of the interferometer of -47.53 microns with a wavelength-by-wavelength spread of 0.389 microns

Approaches for Achieving Broadband Achromatic Phase Shifts for Visible Nulling Coronagraphy

Visible nulling coronagraphy is one of the few approaches to the direct detection and characterization of Jovian and Terrestrial exoplanets that works with segmented aperture telescopes. Jovian and Terrestrial planets require at least 10(exp -9) and 10(exp -10) image plane contrasts, respectively, within the spectral bandpass and thus require a nearly achromatic pi-phase difference between the arms of the interferometer. An achromatic pi-phase shift can be achieved by several techniques, including sequential angled thick glass plates of varying dispersive materials, distributed thin-film multilayer coatings, and techniques that leverage the polarization-dependent phase shift of total-internal reflections. Herein we describe two such techniques: sequential thick glass plates and Fresnel rhomb prisms. A viable technique must achieve the achromatic phase shift while simultaneously minimizing the intensity difference, chromatic beam spread and polarization variation between each arm. In this paper we describe the above techniques and report on efforts to design, model, fabricate, align the trades associated with each technique that will lead to an implementations of the most promising one in Goddard's Visible Nulling Coronagraph (VNC)

The role of the bow shock in solar wind-magnetosphere coupling

In this paper we examine the role of the bow shock in coupling solar wind energy to the magnetosphere using global magnetohydrodynamic simulations of the solar wind-magnetosphere interaction with southward IMF. During typical solar wind conditions, there are two significant dynamo currents in the magnetospheric system, one in the high-latitude mantle region tailward of the cusp and the other in the bow shock. As the magnitude of the (southward) IMF increases and the solar wind becomes a low Mach number flow, there is a significant change in solar wind-magnetosphere coupling. The high-latitude magnetopause dynamo becomes insignificant compared to the bow shock and a large load appears right outside the magnetopause. This leaves the bow shock current as the only substantial dynamo current in the system, and the only place where a significant amount of mechanical energy is extracted from the solar wind. That energy appears primarily as electromagnetic energy, and the Poynting flux generated at the bow shock feeds energy back into the plasma, reaccelerating it to solar wind speeds. Some small fraction of that Poynting flux is directed into the magnetosphere, supplying the energy needed for magnetospheric dynamics. Thus during periods when the solar wind flow has a low Mach number, the main dynamo in the solar wind-magnetosphere system is the bow shock

Trade and market in conflict development and conflict resolution in Nigeria: scoping study report to the UK department for International Development.

This study of trade related conflict and its resolution in Nigeria’s was prompted by the needs of policy makers concerned with improving market access for the poor. There is a lack of published material analysing links between trade/markets and conflict development/conflict resolution. The study is based on a literature review, a small number of interviews in Nigeria and UK and a one-day workshop:it was conceived as a pilot to identify areas for future research. The informality of Nigeria’s agricultural produce trade has the potential to promote both cooperation and conflict. The food marketing chains are complex networks extending across the country, and often involve diverse ethnic, religious and social groups. For the most part these linkages work extremely effectively, drawing on substantial inter-gender, inter-ethnic and inter-religious cooperation,often built up over generations.Nonetheless, there is potential for