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Quantum heat engines based on electronic Mach-Zehnder interferometers

We theoretically investigate the thermoelectric properties of heat engines based on Mach-Zehnder interferometers. The energy dependence of the transmission amplitudes in such setups arises from a difference in the interferometer arm lengths. Any thermoelectric response is thus of purely quantum-mechanical origin. In addition to an experimentally established three-terminal setup, we also consider a

Quantum heat engine based on photon-assisted Cooper pair tunneling

We propose and analyze a simple mesoscopic quantum heat engine that exhibits both high power and high efficiency. The system consists of a biased Josephson junction coupled to two microwave cavities, with each cavity coupled to a thermal bath. Resonant Cooper pair tunneling occurs with the exchange of photons between cavities, and a temperature difference between the baths can naturally lead to a

Mach-Zehnder interferometry with periodic voltage pulses

We investigate theoretically a Mach-Zehnder interferometer driven by a time-dependent voltage. Motivated by recent experiments, we focus on a train of Lorentzian voltage pulses which we compare to a sinusoidal and a constant voltage. We discuss the visibilities of Aharonov-Bohm oscillations in the current and in the noise. For the current, we find a strikingly different behavior in the driven as c

Proposal for an ac spin current source

We propose an ac current source that can be tuned from a pure charge to a pure spin current source. The device consists of two mesoscopic capacitors attached to a two-dimensional strip of a topological insulator. The change from charge to spin current is controlled by an offset in the top gate potentials that drive the capacitors. In addition to this setup, which anticipates the experimental reali

Emission of time-bin entangled particles into helical edge states

We propose a single-particle source which emits into the helical edge states of a two-dimensional quantum spin Hall insulator. Without breaking time-reversal symmetry, this source acts like a pair of noiseless single-electron emitters which each inject separately into a chiral edge state. By locally breaking time-reversal symmetry, the source becomes a proper single-particle emitter which exhibits

Superfluid drag of two-species Bose-Einstein condensates in optical lattices

We study two-species Bose-Einstein condensates in quasi-two-dimensional optical lattices of varying geometry and potential depth. Based on the numerically exact Bloch and Wannier functions obtained using the plane-wave expansion method, we quantify the drag (entrainment coupling) between the condensate components. This drag originates from the (short-range) interspecies interaction and increases w

Assessment of the limiting spatial resolution of an MRI scanner by direct analysis of the edge spread function

Limiting spatial resolution is a key metric of the quality of magnetic resonance MR images, which can provide an indication of the smallest region that can effectively be imaged. In this paper a novel methodology for measuring the limiting spatial resolution of MR images is mathematically analyzed and successfully implemented on phantom images. The methodology presented in this paper is based on a

Physical Implementations of Quantum Absorption Refrigerators

Absorption refrigerators are autonomous thermal machines that harness the spontaneous flow of heat from a hot bath into the environment in order to perform cooling. Here we discuss quantum realizations of absorption refrigerators in two different settings: namely, cavity and circuit quantum electrodynamics. We first provide a unified description of these machines in terms of the concept of virtual

Current and Emerging Technologies for Cardiovascular Imaging

Cardiovascular disease is the leading cause of death in the western world. With the application of theoretical physics to the clinic, a variety of imaging technologies are available to the physician for diagnosing and accurately quantifying disease progression. These tools can influence how therapies are applied and impact patient outcome. Radiographic methods based on x-rays are used for diagnosi

A portrait of facial recognition : Tracing a history of a statistical way of seeing

Automated facial recognition methods have become widely used as a way to ascertain the identity of individuals. Yet the methods by which facial recognition technologies (FRT) operate – the machinic performance of the perception of the human face – are often invisible to those under their gaze. This article investigates the machinic perception of the face through an FRT method known as eigenface, i

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Human use of natural resources poses a great challenge to social-ecological and socio-technical sys- tems alike: supply risks, pollutant and greenhouse gas emissions, waste generation on the one hand, but also issues of global justice and societal well-being on the other hand. In order to test potential im- pacts of developments and strategies relevant to resource policy, the SimRess project first

Pain management after total hip arthroplasty at five different Danish hospitals : A prospective, observational cohort study of 501 patients

BACKGROUND: The available literature does not present a "gold standard" for post-operative pain treatment after total hip arthroplasty (THA). The aim of this prospective observational study was to explore and document post-operative pain treatment, including outcomes, in a large cohort of patients undergoing THA at five different Danish hospitals.METHODS: This prospective, multicentre, observation

Integration of cross-flow filtration in the fruit juice industry

The market for membrane technology in the food and beverage industries increased during the last two decades to a market volume of about € 150 million and is now the second biggest industrial market for membranes after municipal water treatment in Europe. The aim of this study is to highlight new application concepts for membrane processes either by replacing conventional separation processes or b