4,045 research outputs found
Nanoscale Quantum Calorimetry with Electronic Temperature Fluctuations
Motivated by the recent development of fast and ultra-sensitive thermometry
in nanoscale systems, we investigate quantum calorimetric detection of
individual heat pulses in the sub-meV energy range. We propose a hybrid
superconducting injector-calorimeter set-up, with the energy of injected pulses
carried by tunneling electrons. Treating all heat transfer events
microscopically, we analyse the statistics of the calorimeter temperature
fluctuations and derive conditions for an accurate measurement of the heat
pulse energies. Our results pave the way for novel, fundamental quantum
thermodynamics experiments, including calorimetric detection of single
microwave photons.Comment: 6 pages, 3 figures plus supplemental material, 8 pages, 1 figur
Evaluating Engagement in Digital Narratives from Facial Data
Engagement researchers indicate that the engagement level of people in a narrative has an influence on people's subsequent story-related attitudes and beliefs, which helps psychologists understand people's social behaviours and personal experience. With the arrival of multimedia, the digital narrative combines multimedia features (e.g. varying images, music and voiceover) with traditional storytelling. Research on digital narratives has been widely used in helping students gain problem-solving and presentation skills as well as supporting child psychologists investigating children's social understanding such as family/peer relationships through completing their digital narratives. However, there is little study on the effect of multimedia features in digital narratives on the engagement level of people.
This research focuses on measuring the levels of engagement of people in digital narratives and specifically on understanding the media effect of digital narratives on people's engagement levels. Measurement tools are developed and validated through analyses of facial data from different age groups (children and young adults) in watching stories with different media features of digital narratives. Data sources used in this research include a questionnaire with Smileyometer scale and the observation of each participant's facial behaviours
Polarization control of single photon quantum orbital angular momentum states
The orbital angular momentum of photons, being defined in an infinitely
dimensional discrete Hilbert space, offers a promising resource for
high-dimensional quantum information protocols in quantum optics. The biggest
obstacle to its wider use is presently represented by the limited set of tools
available for its control and manipulation. Here, we introduce and test
experimentally a series of simple optical schemes for the coherent transfer of
quantum information from the polarization to the orbital angular momentum of
single photons and vice versa. All our schemes exploit a newly developed
optical device, the so-called "q-plate", which enables the manipulation of the
photon orbital angular momentum driven by the polarization degree of freedom.
By stacking several q-plates in a suitable sequence, one can also access to
higher-order angular momentum subspaces. In particular, we demonstrate the
control of the orbital angular momentum degree of freedom within the
subspaces of and per photon. Our experiments prove
that these schemes are reliable, efficient and have a high fidelity.Comment: 9 pages, 8 figure
Non-rigid image registration to reduce beam-induced blurring of cryo-electron microscopy images
Microscopic imaging and technolog
Lateral and normal forces between patterned substrates induced by nematic fluctuations
We consider a nematic liquid crystal confined by two parallel flat substrates
whose anchoring conditions vary periodically in one lateral direction. Within
the Gaussian approximation, we study the effective forces between the patterned
substrates induced by the thermal fluctuations of the nematic director. The
shear force oscillates as function of the lateral shift between the patterns on
the lower and the upper substrates. We compare the strength of this
fluctuation-induced lateral force with the lateral van der Waals force arising
from chemically structured adsorbed monolayers. The fluctuation-induced force
in normal direction is either repulsive or attractive, depending on the model
parameters.Comment: 9 pages, 9 figure
- …