1.5k citations · 4k across the 60 of their papers we have counts for
60 papers
Quantum Classification through Tournament Voting for Robust Single-Shot Inference
Anastasja D. Helgesen, Jan-Åke Larsson, Michael Felsberg
Quantum machine learning (QML) promises powerful classification capabilities, but suffers from fragile output encodings and high sampling demands -- especially in multiclass settin…
Certainty In, Certainty Out: REVQCs for Quantum Machine Learning
Hannah Helgesen, Michael Felsberg, Jan-Åke Larsson
The field of Quantum Machine Learning (QML) has emerged recently in the hopes of finding new machine learning protocols or exponential speedups for classical ones. Apart from probl…
Efficient contextual ontological model of -qubit stabilizer quantum mechanics
Christoffer Hindlycke, Jan-Åke Larsson
The most well-known tool for studying contextuality in quantum computation is the n-qubit stabilizer state tableau representation. We provide an extension that describes not only t…
Kochen-Specker Contextuality
Costantino Budroni, Adán Cabello, Otfried Gühne +2
A central result in the foundations of quantum mechanics is the Kochen-Specker theorem. In short, it states that quantum mechanics is in conflict with classical models in which the…
Conjugate Logic
Niklas Johansson, Felix Huber, Jan-Åke Larsson
We propose a conjugate logic that can capture the behavior of quantum and quantum-like systems. The proposal is similar to the more generic concept of epistemic logic: it encodes k…
Quantum Simulation Logic, Oracles, and the Quantum Advantage
Niklas Johansson, Jan-Åke Larsson
Query complexity is a common tool for comparing quantum and classical computation, and it has produced many examples of how quantum algorithms differ from classical ones. Here we i…
Comment on "Inherent security of phase coding quantum key distribution systems against detector blinding attacks" [Laser Phys. Lett. 15, 095203 (2018)]
Aleksey Fedorov, Ilja Gerhardt, Anqi Huang +8
This is a brief comment on the Letter by Balygin and his coworkers [Laser Phys. Lett. 15, 095203 (2018)]. We point out an error that invalidates the Letter's conclusions.
Comment on "The photon identification loophole in EPRB experiments: computer models with single-wing selection"
Mateus Araújo, Philippe Grangier, Jan-Åke Larsson
Contrary to the claims made in Ref. [1], the recent Bell tests by Giustina et al. and Shalm et al. do not suffer from a "photon identification loophole". The model discussed in Ref…
Postselection-loophole-free Bell violation with genuine time-bin entanglement
Francesco Vedovato, Costantino Agnesi, Marco Tomasin +4
Entanglement is an invaluable resource for fundamental tests of physics and the implementation of quantum information protocols such as device-independent secure communications. In…
Tight Bounds for the Pearle-Braunstein-Caves Chained Inequality Without the Fair-Coincidence Assumption
Jonathan Jogenfors, Jan-Åke Larsson
In any Bell test, loopholes can cause issues in the interpretation of the results, since an apparent violation of the inequality may not correspond to a violation of local realism.…
Realization of Shor's Algorithm at Room Temperature
Niklas Johansson, Jan-Åke Larsson
Shor's algorithm can find prime factors of a large number more efficiently than any known classical algorithm. Understanding the properties that gives the speedup is essential for…
Comment on "Franson Interference Generated by a Two-Level System"
Jonathan Jogenfors, Adán Cabello, Jan-Åke Larsson
In a recent Letter [Phys. Rev. Lett. 118, 030501 (2017)], Peiris, Konthasinghe, and Muller report a Franson interferometry experiment using pairs of photons generated from a two-le…
High-Visibility Time-Bin Entanglement for Testing Chained Bell Inequalities
Marco Tomasin, Elia Mantoan, Jonathan Jogenfors +3
The violation of Bell's inequality requires a well-designed experiment to validate the result. In experiments using energy-time and time-bin entanglement, initially proposed by Fra…
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…
Contextuality and Nonlocality in Decaying Multipartite Systems
Beatrix C. Hiesmayr, Jan-Å ke Larsson
Everyday experience supports the existence of physical properties independent of observation in strong contrast to the predictions of quantum theory. In particular, existence of ph…
Thermodynamical cost of some interpretations of quantum theory
Adán Cabello, Mile Gu, Otfried Gühne +2
The interpretation of quantum theory is one of the longest-standing debates in physics. Type I interpretations see quantum probabilities as determined by intrinsic properties of th…
Efficient classical simulation of the Deutsch-Jozsa and Simon's algorithms
Niklas Johansson, Jan-Åke Larsson
A long-standing aim of quantum information research is to understand what gives quantum computers their advantage. This requires separating problems that need genuinely quantum res…
Efficient classical simulation of the Deutsch-Jozsa algorithm
Niklas Johansson, Jan-Åke Larsson
In 1985, David Deutsch challenged the Church-Turing thesis by stating that his quantum model of computation "could, in principle, be built and would have many remarkable properties…
Postselection-Loophole-Free Bell Test Over an Installed Optical Fiber Network
Gonzalo Carvacho, Jaime Cariñe, Gabriel Saavedra +9
Device-independent (DI) quantum communication will require a loophole-free violation of Bell inequalities. In typical scenarios where line-of-sight between the communicating partie…
Necessary and Sufficient Conditions for Extended Noncontextuality in a Broad Class of Quantum Mechanical Systems
Janne V. Kujala, Ehtibar N. Dzhafarov, Jan-Åke Larsson
The notion of (non)contextuality pertains to sets of properties measured one subset (context) at a time. We extend this notion to include so-called inconsistently connected systems…
Hacking energy-time entanglement-based systems with classical light
Jonathan Jogenfors, Ashraf M. Elhassan, Johan Ahrens +2
Photonic systems based on energy-time entanglement have been proposed to test local realism using the Bell inequality. A violation of this inequality normally also certifies securi…
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…
Contextuality in Three Types of Quantum-Mechanical Systems
Ehtibar N. Dzhafarov, Janne V. Kujala, Jan-Åke Larsson
We present a formal theory of contextuality for a set of random variables grouped into different subsets (contexts) corresponding to different, mutually incompatible conditions. Wi…
Loopholes in Bell Inequality Tests of Local Realism
Jan-Åke Larsson
Bell inequalities are intended to show that local realist theories cannot describe the world. A local realist theory is one where physical properties are defined prior to and indep…