1.5k citations · 5.8k across the 39 of their papers we have counts for
37 papers · 1 filter
Light polarization measurements in tests of macrorealism
Eugenio Roldán, Johannes Kofler, Carlos Navarrete-Benlloch
According to the world view of macrorealism, the properties of a given system exist prior to and independent of measurement, which is incompatible with quantum mechanics. Leggett a…
Cosmic Bell Test: Measurement Settings from Milky Way Stars
Johannes Handsteiner, Andrew S. Friedman, Dominik Rauch +17
Bell's theorem states that some predictions of quantum mechanics cannot be reproduced by a local-realist theory. That conflict is expressed by Bell's inequality, which is usually d…
Significant-loophole-free test of Bell's theorem with entangled photons
Marissa Giustina, Marijn A. M. Versteegh, Sören Wengerowsky +19
Local realism is the worldview in which physical properties of objects exist independently of measurement and where physical influences cannot travel faster than the speed of light…
No Fine theorem for macrorealism: Limitations of the Leggett-Garg inequality
Lucas Clemente, Johannes Kofler
Tests of local realism and macrorealism have historically been discussed in very similar terms: Leggett-Garg inequalities follow Bell inequalities as necessary conditions for class…
Completely Device Independent Quantum Key Distribution
E. A. Aguilar, R. Ramanathan, J. Kofler +1
Quantum key distribution (QKD) is a provably secure way for two distant parties to establish a common secret key, which then can be used in a classical cryptographic scheme. Using…
Requirements for a loophole-free photonic Bell test using imperfect setting generators
Johannes Kofler, Marissa Giustina, Jan-Åke Larsson +1
Experimental violations of Bell inequalities are in general vulnerable to so-called "loopholes." In this work, we analyse the characteristics of a loophole-free Bell test with phot…
Delayed-choice gedanken experiments and their realizations
Xiao-song Ma, Johannes Kofler, Anton Zeilinger
The wave-particle duality dates back to Einstein's explanation of the photoelectric effect through quanta of light and de Broglie's hypothesis of matter waves. Quantum mechanics us…
On the equivalence of Clauser-Horne and Eberhard inequality based tests
Andrei Khrennikov, Sven Ramelow, Rupert Ursin +3
Recently, the results of the first experimental test for entangled photons closing the detection loophole (also referred to as the fair sampling loophole) were published (Vienna, 2…
Bell violation with entangled photons, free of the coincidence-time loophole
Jan-Åke Larsson, Marissa Giustina, Johannes Kofler +3
In a local realist world view, physical properties are defined prior to and independent of measurement, and no physical influence can propagate faster than the speed of light. Prop…
Bell violation with entangled photons, free of the fair-sampling assumption
Marissa Giustina, Alexandra Mech, Sven Ramelow +9
The violation of a Bell inequality is an experimental observation that forces one to abandon a local realistic worldview, namely, one in which physical properties are (probabilisti…
Quantum information and randomness
Johannes Kofler, Anton Zeilinger
This is an article for a special edition of "European Review" with a focus on the topic "Causality".
A Snapshot of Foundational Attitudes Toward Quantum Mechanics
Maximilian Schlosshauer, Johannes Kofler, Anton Zeilinger
Foundational investigations in quantum mechanics, both experimental and theoretical, gave birth to the field of quantum information science. Nevertheless, the foundations of quantu…
Experimental quantum teleportation over a high-loss free-space channel
Xiao-Song Ma, Sebastian Kropatschek, William Naylor +5
We present a high-fidelity quantum teleportation experiment over a high-loss free-space channel between two laboratories. We teleported six states of three mutually unbiased bases…
Condition for macroscopic realism beyond the Leggett-Garg inequalities
Johannes Kofler, Caslav Brukner
In 1985, Leggett and Garg put forward the concept of macroscopic realism (macrorealism) and, in analogy to Bell's theorem, derived a necessary condition in terms of inequalities, w…
Quantum erasure with causally disconnected choice
Xiao-song Ma, Johannes Kofler, Angie Qarry +9
The counterintuitive features of quantum physics challenge many common-sense assumptions. In an interferometric quantum eraser experiment, one can actively choose whether or not to…
Einstein-Podolsky-Rosen correlations from colliding Bose-Einstein condensates
Johannes Kofler, Mandip Singh, Maximilian Ebner +3
We propose an experiment which can demonstrate quantum correlations in a physical scenario as discussed in the seminal work of Einstein, Podolsky and Rosen. Momentum-entangled mass…
Quantum teleportation using active feed-forward between two Canary Islands
Xiao-song Ma, Thomas Herbst, Thomas Scheidl +11
Quantum teleportation [1] is a quintessential prerequisite of many quantum information processing protocols [2-4]. By using quantum teleportation, one can circumvent the no-cloning…
Experimental delayed-choice entanglement swapping
Xiao-song Ma, Stefan Zotter, Johannes Kofler +4
Motivated by the question, which kind of physical interactions and processes are needed for the production of quantum entanglement, Peres has put forward the radical idea of delaye…
Are there fundamental limits for observing quantum phenomena from within quantum theory?
Johannes Kofler, Caslav Brukner
Does there exist a limit for the applicability of quantum theory for objects of large mass or size, or objects whose states are of large complexity or dimension of the Hilbert spac…
Feasibility of 300 km Quantum Key Distribution with Entangled States
Thomas Scheidl, Rupert Ursin, Alessandro Fedrizzi +8
A significant limitation of practical quantum key distribution (QKD) setups is currently their limited operational range. It has recently been emphasized (X. Ma, C.-H. F. Fung, and…
Experimental generation of single photons via active multiplexing
Xiao-song Ma, Stefan Zotter, Johannes Kofler +2
An on-demand single-photon source is a fundamental building block in quantum science and technology. We experimentally demonstrate the proof of concept for a scheme to generate on-…
Entanglement between smeared field operators in the Klein-Gordon vacuum
Magdalena Zych, Fabio Costa, Johannes Kofler +1
Quantum field theory is the application of quantum physics to fields. It provides a theoretical framework widely used in particle physics and condensed matter physics. One of the m…
Macroscopic realism and spatiotemporal continuity
Johannes Kofler, Nikola Buric, Caslav Brukner
Macroscopic realism, as introduced by Leggett and Garg, is the world view in which properties of macroscopic systems exist independent of and are not influenced by measurement. Mot…
Experimental violation of a Bell inequality with two different degrees of freedom of entangled particle pairs
Xiao-song Ma, Angie Qarry, Johannes Kofler +2
We demonstrate hybrid entanglement of photon pairs via the experimental violation of a Bell inequality with two different degrees of freedom (DOF), namely the path (linear momentum…