Full Frequency Back-Action Spectrum of a Single Electron Transistor during Qubit read-out

We calculate the spectral density of voltage fluctuations in a Single Electron Transistor (SET), biased to operate in a transport mode where tunneling events are correlated due to Coulomb interaction. The whole spectrum from low frequency shot noise to quantum noise at frequencies comparable to the SET charging energy $(E_{C}/\hbar)$ is considered. We discuss the back-action during read-out of a charge qubit and conclude that single-shot read-out is possible using the Radio-Frequency SET.Comment: 4 pages, 5 figures, submitted to PR

Measuring charge based quantum bits by a superconducting single-electron transistor

Single-electron transistors have been proposed to be used as a read-out device for Cooper pair charge qubits. Here we show that a coupled superconducting transistor at a threshold voltage is much more effective in measuring the state of a qubit than a normal-metal transistor at the same voltage range. The effect of the superconducting gap is to completely block the current through the transistor when the qubit is in the logical state 1, compared to the mere diminishment of the current in the normal-metal case. The time evolution of the system is solved when the measuring device is driven out of equilibrium and the setting is analysed numerically for parameters accessible by lithographic aluminium structures.Comment: 4 pages, 3 figures, submitted to Phys.Rev.Lett., RevTex

Full frequency voltage noise spectral density of a single electron transistor

We calculate the full frequency spectral density of voltage fluctuations in a Single Electron Transistor (SET), used as an electrometer biased above the Coulomb threshold so that the current through the SET is carried by sequential tunnel events. We consider both a normal state SET and a superconducting SET. The whole spectrum from low frequency telegraph noise to quantum noise at frequencies comparable to the SET charging energy $(E_{C}/\hbar)$, and high frequency Nyquist noise is described. We take the energy exchange between the SET and the measured system into account using a real-time diagrammatic Keldysh technique. The voltage fluctuations determine the back-action of the SET onto the measured system and we specifically discuss the case of superconducting charge qubit read-out and measuring the so-called Coulomb staircase of a single Cooper pair box.Comment: 14 pages, 18 figures, submitted to PR

Real-world comparative effectiveness of ARNI versus ACEi/ARB in HF with reduced or mildly reduced ejection fraction

Aims Sacubitril/valsartan is a first-in-class angiotensin receptor-neprilysin inhibitor (ARNI) with a class-1 guideline recommendation. We assessed the real-world effectiveness of ARNI versus angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEi/ARB) on all-cause and cardiovascular (CV)-related mortality and hospitalizations in heart failure (HF) with reduced or mildly reduced ejection fraction (EF). Methods Patient-level clinical, laboratory, drug dispensation, hospitalization, and mortality data were derived from the Swedish Heart Failure Registry (SwedeHF) and interlinked databases (1 April 2016-31 December 2020). Eligible ARNI:ACEi/ARB patients (n = 7275:24,604) had a left ventricular EF &amp;lt; 50%. Mortality and hospitalizations with ARNI (&amp;lt;= 3 months pre-/post-1 April 2016 index [SwedeHF]; n = 1506) versus ACEi/ARB (&amp;lt;= 3 months post-index; n = 17,108) were assessed using propensity score matching (1:1 ratio) with clinical variables, and sensitivity analysis (1:2/1:3 with, and 1:2 without clinical variables). Results ARNI induced a 23% reduction in all-cause mortality versus ACEi/ARB (1:1 hazard ratio [HR; 95% confidence interval (CI)]: 0.77 [0.63-0.95], p = 0.013), and a non-significant 23% relative risk reduction in CV-related mortality (0.77 [0.54-1.09], p = 0.13), but no difference in all-cause or CV-related hospitalization (1.02 [0.91-1.13]; p = 0.76; 1.01 [0.91-1.15]; p = 0.84, respectively). Sensitivity analyses confirmed all-cause mortality was reduced for ARNI versus ACEi/ARB (HR 0.90 [95% CI 0.82-0.99], p = 0.026), but not CV-related mortality (HR 1.04 [95% CI 0.89-1.22], p = 0.63). Conclusions In this nationwide real-world study including a population of patients with HF with reduced or mildly reduced EF, ARNI as part of guideline-led Swedish clinical practice was associated with a statistically significant relative risk reduction in all-cause mortality compared with ACEi/ARB.Funding Agencies|University of Gothenburg - Novartis Sweden AB</p

A density functional for sparse matter

Sparse matter is abundant and has both strong local bonds and weak nonbonding forces, in particular nonlocal van der Waals (vdW) forces between atoms separated by empty space. It encompasses a broad spectrum of systems, like soft matter, adsorption systems and biostructures. Density-functional theory (DFT), long since proven successful for dense matter, seems now to have come to a point, where useful extensions to sparse matter are available. In particular, a functional form, vdW-DF (Dion et al 2004 Phys. Rev. Lett. 92 246401; Thonhauser et al 2007 Phys. Rev. B 76 125112), has been proposed for the nonlocal correlations between electrons and applied to various relevant molecules and materials, including to those layered systems like graphite, boron nitride and molybdenum sulfide, to dimers of benzene, polycyclic aromatic hydrocarbons (PAHs), doped benzene, cytosine and DNA base pairs, to nonbonding forces in molecules, to adsorbed molecules, like benzene, naphthalene, phenol and adenine on graphite, alumina and metals, to polymer and carbon nanotube (CNT) crystals, and hydrogen storage in graphite and metal–organic frameworks (MOFs), and to the structure of DNA and of DNA with intercalators. Comparison with results from wavefunction calculations for the smaller systems and with experimental data for the extended ones show the vdW-DF path to be promising. This could have great ramifications

Research &amp; Innovation Platform for Electric Road Systems

The Swedish government has prioritized achieving a fossil fuel-independent vehicle fleet by 2030 which will require radical transformation of the transport industry. Electrifying the vehicle fleet forms an important part of this transformation. For light vehicles, electrification using batteries and charging during parking is already well advanced. For city buses, charging at bus stops and bus depots is being developed, but for heavy, long-distance road transport, batteries with enough capacity to provide sufficient range would be too cumbersome and too much time would have to be spent stationary for charging. One solution might be the introduction of electric roads, supplying the moving vehicle with electricity both to power running and for charging. In the longer term, this approach could also be used for light vehicles and buses. The objective of the Research and Innovation Platform for Electric Roads was to enhance Swedish and Nordic research and innovation in this field, this has been done by developing a joint knowledge base through collaboration with research institutions, universities, public authorities, regions, and industries. The work of the Research and Innovation Platform was intended to create clarity concerning the socioeconomic conditions, benefits, and other effects associated with electric roads. We have investigated the benefits from the perspectives of various actors, implementation strategies, operation and maintenance standards, proposed regulatory systems, and factors conducive of the acceptance and development of international collaborative activities. The project commenced in the autumn of 2016 and the main research continued until December 2019, the work during year 2020 has been focused on knowledge spread and coordination with the Swedish-Germany research collaboration on ERS (CollERS). The results of the Research and Innovation Platform have been disseminated through information meetings, seminars, and four annual international conferences. Reports have been published in the participating partners’ ordinary publication series and on www.electricroads.org. The project was funded by Strategic Vehicle Research and Innovation (FFI) and the Swedish Transport Administration.FoI plattform för elväga

Research &amp; Innovation Platform for Electric Road Systems

The Swedish government has prioritized achieving a fossil fuel-independent vehicle fleet by 2030 which will require radical transformation of the transport industry. Electrifying the vehicle fleet forms an important part of this transformation. For light vehicles, electrification using batteries and charging during parking is already well advanced. For city buses, charging at bus stops and bus depots is being developed, but for heavy, long-distance road transport, batteries with enough capacity to provide sufficient range would be too cumbersome and too much time would have to be spent stationary for charging. One solution might be the introduction of electric roads, supplying the moving vehicle with electricity both to power running and for charging. In the longer term, this approach could also be used for light vehicles and buses. The objective of the Research and Innovation Platform for Electric Roads was to enhance Swedish and Nordic research and innovation in this field, this has been done by developing a joint knowledge base through collaboration with research institutions, universities, public authorities, regions, and industries. The work of the Research and Innovation Platform was intended to create clarity concerning the socioeconomic conditions, benefits, and other effects associated with electric roads. We have investigated the benefits from the perspectives of various actors, implementation strategies, operation and maintenance standards, proposed regulatory systems, and factors conducive of the acceptance and development of international collaborative activities. The project commenced in the autumn of 2016 and the main research continued until December 2019, the work during year 2020 has been focused on knowledge spread and coordination with the Swedish-Germany research collaboration on ERS (CollERS). The results of the Research and Innovation Platform have been disseminated through information meetings, seminars, and four annual international conferences. Reports have been published in the participating partners’ ordinary publication series and on www.electricroads.org. The project was funded by Strategic Vehicle Research and Innovation (FFI) and the Swedish Transport Administration