On a biphononic origin of the 1125 cm^(-1) absorption band in cuprous oxide

We report on the IR spectroscopic studies in both reflection (50-900 cm^{-1}) and transmission (900-3000 cm^{-1}) mode of the vibration spectrum of the cuprous oxide. A detailed analysis based on a comparison of the temperature dependences of the absorption band at 1125 cm^{-1} and of IR and Raman active fundamental vibrations results in assignment of the former to a biphonon.Comment: 5 pages, 5 figures (to appear in Phys.Lett. A

Entangled Wavefunctions from Classical Oscillator Amplitudes

In the first days of quantum mechanics Dirac pointed out an analogy between the time-dependent coefficients of an expansion of the Schr\"odinger equation and the classical position and momentum variables solving Hamilton's equations. Here it is shown that the analogy can be made an equivalence in that, in principle, systems of classical oscillators can be constructed whose position and momenta variables form time-dependent amplitudes which are identical to the complex quantum amplitudes of the coupled wavefunction of an N-level quantum system with real coupling matrix elements. Hence classical motion can reproduce quantum coherence.Comment: extended versio

Summer Universities for Women in Computer Science

A cross-university approach will be discussed that reflects moneducation, networking, and gender oriented organizational reforms in university programs. The concept was developed in Germany in 1997 as a national approach. Each year “Informatica Feminale” (www. Informatica-feminale.de) attracts more than 70 female lectures from universities, research, or industry to give courses on all topics of computer science oriented to the existing university curricula. Participants are female students as well as women interested in further education. The approach has won an European award for best practice. Since 2003 Austria provides a similar project called the “ditact-women’s IT summer studies” (www.ditact.ac.at). Another project will be located in New Zealand in 2005 as the “Computing Women Conference” (www/ cwc.org.nz)

Resonant two-photon excitation of 1s paraexcitons in Cuprous Oxide

We have created paraexcitons in Cuprous Oxide via resonant two-photon generation, and examined their population dynamics by means of time-correlated single photon detection. Confining the excitons to a constant volume in a harmonic potential trap made with inhomogeneous applied stress along the [001] axis, we find that paraexcitons are created directly, and orthoexcitons appear primarily through the well-known excitonic Auger process. Hot excitons are also created via a three-photon process when the IR laser is non-resonant. Also we generate excitons with two colliding pulses, and the luminescence is weaker than that from one beam excitation with same total laser power. These results show that resonant one-beam two-photon generation of paraexcitons is a promising way to pursue Bose-Einstein condensation of paraexcitons.Comment: 22 pages, 9 figure

Kollaborationstechnologien in DAX30 Konzernen - Wie relevant ist die gezielte Endnutzeraktivierung bei und nach Einführung von Microsoft Teams und Co.?

In a fast-evolving world, technological innovations can disrupt existing processes and behaviors. The rising trend of digital collaboration brings new possibilities through technology and can have a significant impact on organizations and their employees. But during the implementation, decision makers tend to focus on the IT-part, leaving their employees with a new application with a broad range of functions which they don’t know what to do with. The new tool also can have complex implications on the way of working and must be learnt from the technical side. This results in the question, whether an individual end-user activation with a comprehensive change management and learning activities would be necessary for the implementation, which will be answered in this thesis “Collaboration technologies in DAX30 companies - How important is a targeted end-user activation during and after the implementation of Microsoft Teams and Co.?”. In order to cover the different aspects of a targeted end user activation the topic was split up into three research questions: 1. How should the skills and attitudes of employees change, so that collaboration technologies are used effectively? 2. What factors need to be considered in the change management for sustainable activation? 3. What is the ideal design of learning formats for an end-user activation? To answer these research questions in a well-founded and valid way, the method of expert interviews was chosen after an extensive literature search. Therefore, 3 experts from this field were interviewed on the topic and the collected qualitative data critically analyzed on the knowledge basis of the literature. Also, this thesis is written in collaboration with the company Ernst & Young GmbH Wirtschaftsprüfungsgesellschaft, which provided information on the topic and experience of experts. The results can be used for organizations to decide on relevance and the way and strategy of implementing a new collaboration technology. They showed, that an implementation can be very complex and that many aspects should be considered for the employees to be able to work effectively with the new technology. Most important is an user centric approach with the needs and expectations of the affected employees at its core, which should be individually developed after a careful analysis of each organization. The skills and attitude toward a new way of collaborating, the mentality in communicating and sharing culture of exchanging work and results should be applied by the employees in order to work effectively. Therefore, a targeted end-user activation is highly recommended during and after the implementation of the new technology