This analysis demonstrates the relevance and robustness of the Theory of Planned Behavior in the prediction of business start-up intentions and subsequent behavior based on longitudinal survey data (2011 and 2012; N=969) from the adult population in Austria and Finland. By doing so, the study addresses two weaknesses in current research: the limited scope of samples used in the majority of prior studies and the scarcity of investigations studying the translation of entrepreneurial intentions into behavior. The article discusses conceptual and methodological issues related to studying the intention-behavior relationship and outlines avenues for future research.2

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Abstract:We perform decoy-state quantum key distribution between a low-Earth-orbit satellite and multiple ground stations located in Xinglong, Nanshan, and Graz, which establish satellite-to-ground secure keys with ~kHz rate per passage of the satellite Micius over a ground station. The satellite thus establishes a secure key between itself and, say, Xinglong, and another key between itself and, say, Graz.Then, upon request from the ground command, Micius acts as a trusted relay. It performs bitwise exclusive OR operations between the two keys and relays the result to one of the ground stations. That way, a secret key is created between China and Europe at locations separated by 7600 km on Earth. These keys are then used for intercontinental quantum-secured communication. This was on the one hand the transmission of images in a one-time pad configuration from China to Austria as well as from Austria to China. Also, a videoconference was performed between the Austrian Academy of Sciences and the Chinese Academy of Sciences, which also included a 280 km optical ground connection between Xinglong and Beijing. Our work points towards an efficient solution for an ultralong-distance global quantum network, laying the groundwork for a future quantum internet.With the growth of internet use and electronic commerce, a secure global network for data protection is necessary. A drawback of traditional public key cryptography is that it is not possible to guarantee it is information theoretically secure. It has been witnessed in history that every advance of encryption has been defeated by advances in hacking. In particular, with the advent of Shor's factoring algorithm [1], most of the currently used cryptographic infrastructure will be defeated by quantum computers.On the contrary, quantum key distribution (QKD) [2] offers unconditional security ensured by the law of physics. QKD uses the fundamental unit of light, single photons, encoded in quantum superposition states which are sent to a distant location. By proper encoding and decoding, two distant parties share strings of random bits called secret keys. However, due to photon loss in the channel, the secure QKD distance by direct transmission of the single photons in optical fibers or terrestrial free space was hitherto limited to a few hundred kilometers [3][4][5][6][7]. Unlike classical bits, the quantum signal in the QKD cannot be noiselessly amplified owing to the quantum no-cloning theorem [8], already contained at the core of Wiesner's proposal of uncopiable quantum money [9], where the security of the QKD is rooted.The main challenge for a practical QKD is to extend the communication range to long distances, ultimately on a global scale. A promising solution to this problem is exploiting satellite and space-based links [10,11]. That way, one can conveniently connect two remote points on Earth with greatly reduced channel loss because most of the photons' propagation path is in empty space with negligible loss and decoherence. In this work, QKD is performed in a ...

Transverse spatial modes of light offer a large state-space with interesting physical properties. For exploiting these special modes in future long-distance experiments, the modes will have to be transmitted over turbulent free-space links. Numerous recent lab-scale experiments have found significant degradation in the mode quality after transmission through simulated turbulence and consecutive coherent detection. Here, we experimentally analyze the transmission of one prominent class of spatial modes-orbital-angular momentum (OAM) modes-through 3 km of strong turbulence over the city of Vienna. Instead of performing a coherent phase-dependent measurement, we employ an incoherent detection scheme, which relies on the unambiguous intensity patterns of the different spatial modes. We use a pattern recognition algorithm (an artificial neural network) to identify the characteristic mode patterns displayed on a screen at the receiver. We were able to distinguish between 16 different OAM mode superpositions with only a ∼1.7% error rate and to use them to encode and transmit small grayscale images. Moreover, we found that the relative phase of the superposition modes is not affected by the atmosphere, establishing the feasibility for performing long-distance quantum experiments with the OAM of photons. Our detection method works for other classes of spatial modes with Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. unambiguous intensity patterns as well, and can be further improved by modern techniques of pattern recognition.The angular momentum of photons consists of two different components. The first one is the spin angular momentum (SAM), which defines the polarization of photons. The second component is the orbital angular momentum (OAM), which corresponds to the spatial phase distribution of the photon. Both components have been used extensively in optical experiments at the lab-scale. Furthermore, polarization has been successfully used in quantum experiments over free-space links on the order of 100 kilometers [1][2][3]. The polarization of a photon, while being easily controllable and immune to atmospherical influences, resides in a two-dimensional state-space. This places an inherent limit on how much information one can send per photon. As a consequence, it sets a tight bound on how much error a quantum key distribution (QKD) system that uses such encoding can tolerate [4,5]. An alternate way to encode information is in the OAM degree-of-freedom of a photon, which offers a theoretically unbounded number of discrete levels [6,7] and is able to improve classical [8-10] communication as well as quantum communication [11,12]. Light carrying OAM has a 'twisted' or helical wave front with an azimuthal phase that varies from 0 to 2 πℓ. The integer ℓ stands for the topological charge or helicity, and ℓℏ is the OAM of the photon [13].T...