1,263 research outputs found
Emergence of a measurement basis in atom-photon scattering
The process of quantum measurement has been a long standing source of debate.
A measurement is postulated to collapse a wavefunction onto one of the states
of a predetermined set - the measurement basis. This basis origin is not
specified within quantum mechanics. According to the theory of decohernce, a
measurement basis is singled out by the nature of coupling of a quantum system
to its environment. Here we show how a measurement basis emerges in the
evolution of the electronic spin of a single trapped atomic ion due to
spontaneous photon scattering. Using quantum process tomography we visualize
the projection of all spin directions, onto this basis, as a photon is
scattered. These basis spin states are found to be aligned with the scattered
photon propagation direction. In accordance with decohernce theory, they are
subjected to a minimal increase in entropy due to the photon scattering, while,
orthogonal states become fully mixed and their entropy is maximally increased.
Moreover, we show that detection of the scattered photon polarization measures
the spin state of the ion, in the emerging basis, with high fidelity. Lastly,
we show that while photon scattering entangles all superpositions of pointer
states with the scattered photon polarization, the measurement-basis states
themselves remain classically correlated with it. Our findings show that photon
scattering by atomic spin superpositions fulfils all the requirements from a
quantum measurement process
Soft power: Power of attraction or confusion?
Despite its popularity soft power remains power of confusion. The paper examines the concept, with a special focus on the nature and sources of soft power. Nye’s notion of soft power is largely ethnocentric and based on the assumption that there is a link between attractiveness and the ability to influence others in international relations. This poses two problems: Firstly, a country has many different actors. Some of them like the attraction and others don’t. Whether the attraction will lead to the ability to influence the policy of the target country depends on which groups in that country find it attractive and how much control they have on policymaking. Secondly, policymaking at the state level is far more complicated than at the personal level; and has different dynamics that emphasise the rational considerations. This leaves little room for emotional elements thus significantly reducing the effect of soft power. Given the nature of soft power being uncontrollable and unpredictable, it would be impossible to wield soft power in any organised and coordinated fashion as Nye suggested. Furthermore, the relationship between two countries is shaped by many complex factors. It is ultimately decided by the geopolitics and strategic interests of nations, in which soft power may play only a limited role. The paper also discusses the link between soft power and nation branding as both concepts are concerned with a nation’s influence on the world stage. Public diplomacy is a subset of nation branding that focuses on the political brand of a nation; whereas nation branding is about how a nation as whole to reshape the international opinions. A successful nation branding campaign will help create a more favourable and lasting image among the international audience thus further enhancing a country’s soft power
High-fidelity state detection and tomography of a single ion Zeeman qubit
We demonstrate high-fidelity Zeeman qubit state detection in a single trapped
88 Sr+ ion. Qubit readout is performed by shelving one of the qubit states to a
metastable level using a narrow linewidth diode laser at 674 nm followed by
state-selective fluorescence detection. The average fidelity reached for the
readout of the qubit state is 0.9989(1). We then measure the fidelity of state
tomography, averaged over all possible single-qubit states, which is 0.9979(2).
We also fully characterize the detection process using quantum process
tomography. This readout fidelity is compatible with recent estimates of the
detection error-threshold required for fault-tolerant computation, whereas
high-fidelity state tomography opens the way for high-precision quantum process
tomography
Branding the nation: Towards a better understanding
This paper aims to clarify some misunderstanding about nation branding. It examines the origins and interpretations of the concept, and draws a comparison between nation branding and commercial branding. A new definition is offered that emphasises the need to shift from “branding” the nation to nation image management
The Image of Taiwan as a Travel Destination: Perspectives from Mainland China
This study presents the perceived and projected image of Taiwan as a travel destination from perspectives from Mainland China. The perceived image of Taiwan was examined by interviewing 28 Mainland Chinese; the projected image of Taiwan was investigated by analyzing articles in China's most popular travel magazines. The different types of images of Taiwan among visitors, nonvisitors, and travel magazines were compared. The projected image changed notably after the opening of Taiwan's tourism to travelers from Mainland China. The results of this study could help destination marketing organizations to assess their marketing strategies for the Mainland Chinese travel market
Denial at the top table: status attributions and implications for marketing
Senior marketing management is seldom represented on the Board of Directors nowadays, reflecting a deteriorating status of the marketing profession. We examine some of the key reasons for marketing’s demise, and discuss how the status of marketing may be restored by demonstrating the value of marketing to the business community. We attribute marketing’s demise to several related key factors: narrow typecasting, marginalisation and limited involvement in product development, questionable marketing curricula, insensitivity toward environmental change, questionable professional standards and roles, and marketing’s apparent lack of accountability to CEOs. Each of these leads to failure to communicate, create, or deliver value within marketing. We argue that a continued inability to deal with marketing’s crisis of representation will further erode the status of the discipline both academically and professionally
Quantum control of Sr in a miniature linear Paul trap
We report on the construction and characterization of an apparatus for
quantum information experiments using Sr ions. A miniature linear
radio-frequency (rf) Paul trap was designed and built. Trap frequencies above 1
MHz in all directions are obtained with 50 V on the trap end-caps and less than
1 W of rf power. We encode a quantum bit (qubit) in the two spin states of the
electronic ground-state of the ion. We constructed all the necessary
laser sources for laser cooling and full coherent manipulation of the ions'
external and internal states. Oscillating magnetic fields are used for coherent
spin rotations. High-fidelity readout as well as a coherence time of 2.5 ms are
demonstrated. Following resolved sideband cooling the average axial vibrational
quanta of a single trapped ion is and a heating rate of
ms is measured.Comment: 8 pages,9 figure
Social media use and impact during the holiday travel planning process
Through an empirical study among holiday travellers, residing in the Former Soviet Union Republics, this paper presents a comprehensive view of role and impact of social media on the whole holiday travel planning process: Before, during and after the trip, providing insights on usage levels, scope of use, level of influence and trust. Findings suggest that social media are predominantly used after holidays for experience sharing. It is also shown that there is a strong correlation between perceived level of influence from social media and changes made in holiday plans prior to final decisions. Moreover, it is revealed that user-generated content is perceived as more trustworthy when compared to official tourism websites, travel agents and mass media advertising
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