Spending time with money: from shared values to social connectivity

This article has been made available through the Brunel Open Access Publishing Fund.There is a rapidly growing momentum driving the development of mobile payment systems for co-present interactions, using near-field communication on smartphones and contactless payment systems. The design (and marketing) imperative for this is to enable faster, simpler, effortless and secure transactions, yet our evidence shows that this focus on reducing transactional friction may ignore other important features around making payments. We draw from empirical data to consider user interactions around financial exchanges made on mobile phones. Our findings examine how the practices around making payments support people in making connections, to other people, to their communities, to the places they move through, to their environment, and to what they consume. While these social and community bonds shape the kinds of interactions that become possible, they also shape how users feel about, and act on, the values that they hold with their co-users. We draw implications for future payment systems that make use of community connections, build trust, leverage transactional latency, and generate opportunities for rich social interactions

Improving water heaters for sustainability

posterBuildings use about 40% of the total U.S. energy demand. Water heaters provide hot water for a variety of building uses including sinks, showers, dishwashers, washing machines, and space heating. Water heaters are the second most energy intensive appliances in a common household. Typically a home water heater's energy sources is natural gas. There are other types of tank water heaters including ultra low NOx, and electric resistance. Figure 1 displays the differences in water heater types. Electric resistance water heaters use electrical grid power. Building owners burdent thec cost of water heating through the initial water heater cost, energy bills, and the communal air pollution they breathe. Burning and extracting non-renewable fuels including natural gas leads to climate change. Water heaters noticeably attribute air pollution to winter inversions have adverse affects on human health. Combusted air pollutants include Carbon Dioxide (CO2), Nitorgen oxides (NOx), and Sulfur oxides (SOx). Pushing towards the future Salt Lake City has set a goal to reduce 80% of green house gases emissions by the year 2040 setting a demand for water heater emissions reduction

Meta-awareness during day and night: the relationship between mindfulness and lucid dreaming.

The present study explored the relationship between lucidity in dreams (awareness of dreams while dreaming) and mindfulness during wakefulness, also considering meditation as a possible moderating variable. An online survey was completed by 528 respondents, of whom 386 (73.1%) had lucid dream experiences. The reported frequency of lucid dreams was found to be positively related to higher dispositional mindfulness in wakefulness. This relationship was only present in those participants who reported acquaintance with meditation. Regarding the dimensions of mindfulness, lucid dream frequency was more strongly associated with mindful presence rather than acceptance. The findings support the notion of an existing relationship between lucidity in dreams and mindfulness during wakefulness, yet it remains unclear whether the relationship is influenced by actual meditation practice or whether it reflects some natural predispositions. Future studies should examine the role of different meditation practices, investigate personality variables that might influence the relationship, and explore how different facets of mindfulness and lucidity interrelate. Keywords: lucid dreaming; mindfulness; meditatio

Symmetric Operation of the Resonant Exchange Qubit

We operate a resonant exchange qubit in a highly symmetric triple-dot configuration using IQ-modulated RF pulses. At the resulting three-dimensional sweet spot the qubit splitting is an order of magnitude less sensitive to all relevant control voltages, compared to the conventional operating point, but we observe no significant improvement in the quality of Rabi oscillations. For weak driving this is consistent with Overhauser field fluctuations modulating the qubit splitting. For strong driving we infer that effective voltage noise modulates the coupling strength between RF drive and the qubit, thereby quickening Rabi decay. Application of CPMG dynamical decoupling sequences consisting of up to n = 32 {\pi} pulses significantly prolongs qubit coherence, leading to marginally longer dephasing times in the symmetric configuration. This is consistent with dynamical decoupling from low frequency noise, but quantitatively cannot be explained by effective gate voltage noise and Overhauser field fluctuations alone. Our results inform recent strategies for the utilization of partial sweet spots in the operation and long-distance coupling of triple-dot qubits.Comment: 6 pages, 5 figure

Negative spin exchange in a multielectron quantum dot

By operating a one-electron quantum dot (fabricated between a multielectron dot and a one-electron reference dot) as a spectroscopic probe, we study the spin properties of a gate-controlled multielectron GaAs quantum dot at the transition between odd and even occupation number. We observe that the multielectron groundstate transitions from spin-1/2-like to singlet-like to triplet-like as we increase the detuning towards the next higher charge state. The sign reversal in the inferred exchange energy persists at zero magnetic field, and the exchange strength is tunable by gate voltages and in-plane magnetic fields. Complementing spin leakage spectroscopy data, the inspection of coherent multielectron spin exchange oscillations provides further evidence for the sign reversal and, inferentially, for the importance of non-trivial multielectron spin exchange correlations.Comment: 8 pages, including 4 main figures and 2 supplementary figurure

Summer Dormancy and Survival of Tall Fescue in Relation to Endophyte Presence

True summer dormancy in temperate perennial grasses is the ability to survive summer stresses by ceasing growth and senescing vegetative tissues independently of water supply, as opposed to summer-active grasses, which respond to rains by continuing growth, but senesce during droughts (Volaire and Norton 2006). Summer dormancy is a common drought-escape mechanism for Mediterranean-origin perennial grasses, but is also being considered as a potentially useful trait in semiarid to humid zones whose climates are not strictly Mediterranean, but where temperate grass survival is threatened by summer heat and water deficits (Malinowski et al. 2005). Moreover, summer dormancy may provide a mechanism for adapting to climate change patterns that exacerbate summer stresses (West et al. 2009). Tall fescue [Lolium arundinaceum (Schreb.) S.J. Darbyshire] populations exhibit a range of summer dormancy potentials from nondormant (summer active) to varying levels of incomplete dormancy, but not complete dormancy (Norton et al. 2006). Summer drought survival of tall fescue is generally aided by symbiosis with a fungal endophyte [Neotyphodium coenophialum (Morgan-Jones & Gams) Glenn, Bacon & Hanlin comb.], and this endophyte is endemic in nearly all native populations of tall fescue (West 1994). Little is known of the influence of the endophyte on the expression of summer dormancy in their grass hosts or of the role of endophytes in host drought survival. We investigated the influence of environment and endophyte presence on expression of summer dormancy and survival in tall fescue in relation to expression of biochemical protectants

How to wire a 1000-qubit trapped ion quantum computer

One of the most formidable challenges of scaling up quantum computers is that of control signal delivery. Today's small-scale quantum computers typically connect each qubit to one or more separate external signal sources. This approach is not scalable due to the I/O limitations of the qubit chip, necessitating the integration of control electronics. However, it is no small feat to shrink control electronics into a small package that is compatible with qubit chip fabrication and operation constraints without sacrificing performance. This so-called "wiring challenge" is likely to impact the development of more powerful quantum computers even in the near term. In this paper, we address the wiring challenge of trapped-ion quantum computers. We describe a control architecture called WISE (Wiring using Integrated Switching Electronics), which significantly reduces the I/O requirements of ion trap quantum computing chips without compromising performance. Our method relies on judiciously integrating simple switching electronics into the ion trap chip - in a way that is compatible with its fabrication and operation constraints - while complex electronics remain external. To demonstrate its power, we describe how the WISE architecture can be used to operate a fully connected 1000-qubit trapped ion quantum computer using ~ 200 signal sources at a speed of ~ 40 - 2600 quantum gate layers per second

Breeding Cool-Season Forage Grasses for a Warming Climate

In many parts of the world, changing climatic conditions are resulting in increased temperatures and more variable precipitation, intensifying the duration and severity of drought, especially in summer. Warming climate is considered one reason for the increasing failure of traditional, summer-active cool-season perennial grasses at the margin of their zone of adaptation in naturally C4 grass-dominated ecosystems of the Southern Great Plains of the USA. Two cool-season perennial forage grasses orchardgrass (Dactylis glomerata L.) and tall fescue (Lolium arundinaceum (Schreb.) Darbysh.) are of major economic and ecological importance in these regions. In 2008, we initiated a breeding program of summer-dormant (Mediterranean) cool-season perennial grasses originating from the Mediterranean Basin, including tall fescue, orchardgrass, and perennial ryegrass. In this publication, we present breeding history and morphological characteristics of cv. Yonatan (also known under research name TAL-02), a new cultivar of summer-dormant tall fescue. Recurrent selection cycles were conducted to develop cv. Yonatan during 2007-2010. Evaluations were performed on several locations across north Texas, Australia and New Zealand during 2015-2020. Yonatan tall fescue has improved forage production and persistence compared with check cultivars Flecha and Chisholm. It also differs from them in terms of wider leaves, earlier maturity, and development of a bulbous storage organ at the base of the tiller. Yonatan is adapted to changing climatic conditions in the Southern Great Plains of the USA, Australia, and New Zealand

Noise suppression using symmetric exchange gates in spin qubits

We demonstrate a substantial improvement in the spin-exchange gate using symmetric control instead of conventional detuning in GaAs spin qubits, up to a factor-of-six increase in the quality factor of the gate. For symmetric operation, nanosecond voltage pulses are applied to the barrier that controls the interdot potential between quantum dots, modulating the exchange interaction while maintaining symmetry between the dots. Excellent agreement is found with a model that separately includes electrical and nuclear noise sources for both detuning and symmetric gating schemes. Unlike exchange control via detuning, the decoherence of symmetric exchange rotations is dominated by rotation-axis fluctuations due to nuclear field noise rather than direct exchange noise.Comment: 5 pages main text (4 figures) plus 5 pages supplemental information (3 figures

Fast spin exchange between two distant quantum dots

The Heisenberg exchange interaction between neighboring quantum dots allows precise voltage control over spin dynamics, due to the ability to precisely control the overlap of orbital wavefunctions by gate electrodes. This allows the study of fundamental electronic phenomena and finds applications in quantum information processing. Although spin-based quantum circuits based on short-range exchange interactions are possible, the development of scalable, longer-range coupling schemes constitutes a critical challenge within the spin-qubit community. Approaches based on capacitative coupling and cavity-mediated interactions effectively couple spin qubits to the charge degree of freedom, making them susceptible to electrically-induced decoherence. The alternative is to extend the range of the Heisenberg exchange interaction by means of a quantum mediator. Here, we show that a multielectron quantum dot with 50-100 electrons serves as an excellent mediator, preserving speed and coherence of the resulting spin-spin coupling while providing several functionalities that are of practical importance. These include speed (mediated two-qubit rates up to several gigahertz), distance (of order of a micrometer), voltage control, possibility of sweet spot operation (reducing susceptibility to charge noise), and reversal of the interaction sign (useful for dynamical decoupling from noise).Comment: 6 pages including 4 figures, plus 8 supplementary pages including 5 supplementary figure