102 research outputs found
Vibronic spectroscopy of an artificial molecule
With advanced fabrication techniques it is possible to make nanoscale
electronic structures that have discrete energy levels. Such structures are
called artificial atoms because of analogy with true atoms. Examples of such
atoms are quantum dots in semiconductor heterostructures and Josephson-junction
qubits. It is also possible to have artificial atoms interacting with each
other. This is an artificial molecule in the sense that the electronic states
are analogous to the ones in a molecule. In this letter we present a different
type of artificial molecule that, in addition to electronic states, also
includes the analog of nuclear vibrations in a diatomic molecule. Some of the
earlier experiments could be interpreted using this analogy, including qubits
coupled to oscillators and qubits driven by an intense field. In our case the
electronic states of the molecule are represented by a Josephson-junction
qubit, and the nuclear separation corresponds to the magnetic flux in a loop
containing the qubit and an LC oscillator. We probe the vibronic transitions,
where both the electronic and vibrational states change simultaneously, and
find that they are analogous to true molecules. The vibronic transitions could
be used for sideband cooling of the oscillator, and we see damping up to
sidebands of order 10.Comment: 5 pages, 4 figure
Effect of Pulsed or Continuous Delivery of Salt on Sensory Perception Over Short Time Intervals
Salt in the human diet is a major risk factor for hypertension and many countries have set targets to reduce
salt consumption. Technological solutions are being sought
to lower the salt content of processed foods without altering their taste. In this study, the approach was to deliver salt solutions in pulses of different concentrations to determine whether a pulsed delivery profile affected sensory perception of salt. Nine different salt profiles were delivered by a Dynataste device and a trained panel assessed their saltiness using timeâintensity and single-score sensory techniques. The profile duration (15 s) was designed to match eating conditions and the effects of intensity and duration of the pulses on sensory perception were investigated. Sensory results from the profiles delivered in either water or in a bouillon base were not statistically different. Maximum perceived salt intensities and the area under the timeâ
intensity curves correlated well with the overall perceived
saltiness intensity despite the stimulus being delivered as
several pulses. The overall saltiness scores for profiles
delivering the same overall amount of sodium were statistically not different from one another suggesting that, in this system, pulsed delivery did not enhance salt
perception but the overall amount of salt delivered in each
profile did affect sensory perception
Motional Averaging in a Superconducting Qubit
Superconducting circuits with Josephson junctions are promising candidates
for developing future quantum technologies. Of particular interest is to use
these circuits to study effects that typically occur in complex
condensed-matter systems. Here, we employ a superconducting quantum bit
(qubit),a transmon, to carry out an analog simulation of motional averaging, a
phenomenon initially observed in nuclear magnetic resonance (NMR) spectroscopy.
To realize this effect, the flux bias of the transmon is modulated by a
controllable pseudo-random telegraph noise, resulting in stochastic jumping of
the energy separation between two discrete values. When the jumping is faster
than a dynamical threshold set by the frequency displacement of the levels, the
two separated spectral lines merge into a single narrow-width,
motional-averaged line. With sinusoidal modulation a complex pattern of
additional sidebands is observed. We demonstrate experimentally that the
modulated system remains quantum coherent, with modified transition
frequencies, Rabi couplings, and dephasing rates. These results represent the
first steps towards more advanced quantum simulations using artificial atoms.Comment: Main text (5 pages and 4 figures) and Supplementary Information (11
pages and 5 figures
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Can information affect sensory perceptions? Evidence from a survey on Italian organic food consumers
This paper aims to investigate the influence of information on consumersâ preferences and sensory perceptions of organic food using a sample of 301 Italian organic food consumers. Consumers stated their preferences for âcore organicâ attributes, labels and information on food products and performed blind and informed tests on strawberry yoghurts and cookies. Data were analysed using descriptive analysis, Mann-Whitney U tests and Wilcoxon signed-rank test. Results revealed that consumers appreciate âcore organicâ attributes, like artisanal production and variability of sensory attributes. Comparing blind and informed tests, results showed that information affects the overall liking of products and consumersâ perception of product-specific sensory attributes. However, the influence of information on sensory perceptions depends on the product category, sensory attributes and the type of information provided
Does corporate reputation matter? Role of social media in consumer intention to purchase innovative food product
The exponential growth of the corporate reputation in food industry has resulted in innovations in every link of its supply chain. There have been studies that have characterized innovation in various industries from the perspective of technology, but far fewer in the area of corporate reputation, consumer perception, and intention towards innovations in food products. This research analyses the innovations in the food industry from the perspective of the consumer and provides a conceptual framework of food innovation stages. The study also investigates the relationship between corporate reputation and intention towards food innovation along with the other components of TPB model with an extension of social media engagement. The results from India and US samples confirm that social media engagement have a significant role to play in creating intention to purchase innovative food products. The study compares the US and Indian samples and identifies differences in subjective norms and perceived behavioural control
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