A5020559291- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Quantum Mechanics and Applications
- Computability, Logic, AI Algorithms
- Complexity and Algorithms in Graphs
- Advanced Operator Algebra Research
- Advanced Topics in Algebra
- Algebraic structures and combinatorial models
- DNA and Biological Computing
- Logic, programming, and type systems
- Game Theory and Applications
- Neural Networks and Reservoir Computing
- Machine Learning and Algorithms
- Advanced Algebra and Logic
- semigroups and automata theory
- Finite Group Theory Research
- Noncommutative and Quantum Gravity Theories
- Quantum many-body systems
- Geometric and Algebraic Topology
- Quantum and electron transport phenomena
- Formal Methods in Verification
- Advancements in Semiconductor Devices and Circuit Design
- Chronic Lymphocytic Leukemia Research
- Quantum-Dot Cellular Automata
- Benford’s Law and Fraud Detection
University of Copenhagen
2016-2024
National University of Singapore
2014-2016
University of Waterloo
2011-2016
University of Bristol
2016
Centre for Quantum Technologies
2012-2015
University of Latvia
2009
The ability to control multidimensional quantum systems is key for the investigation of fundamental science and development advanced technologies. Here we demonstrate a integrated photonic platform able robustly generate, analyze high-dimensional entanglement. We realize programmable bipartite entangled system with dimension up $15 \times 15$ on large-scale silicon-photonics circuit. device integrates more than 550 components single chip, including 16 identical photon-pair sources. verify...
A quantum network promises to enable long distance communication, and assemble small devices into a large computing cluster. Each node can thereby be seen as few qubit computer. Qubits sent over direct physical links connecting nearby nodes, or by means of teleportation pre-established entanglement amongst distant nodes. Such pre-shared effectively forms shortcut - virtual link which used exactly once. Here, we present an abstraction that allows ideas from computer science applied the...
Quantum thermodynamics is a research field that aims at fleshing out the ultimate limits of thermodynamic processes in deep quantum regime. A complete picture thermodynamical naturally allows for auxiliary systems dubbed 'catalysts', i.e., any physical facilitating state transformations while remaining essentially intact their state, like an system, clock, or actual catalyst. In this work, we present comprehensive analysis power and limitation such thermal catalysis. Specifically, provide...
Over 50 years ago, Lovász proved that two graphs are isomorphic if and only they admit the same number of homomorphisms from any graph. Other equivalence relations on graphs, such as cospectrality or fractional isomorphism, can be characterized by equality homomorphism counts an appropriately chosen class graphs. Dvořák [J. Graph Theory 2010] showed taking this to treewidth at most k yields a tractable relaxation graph isomorphism known k-dimensional Weisfeiler-Leman equivalence. Together...
We investigate quantum and nonsignaling generalizations of perfect matchings in graphs using nonlocal games. Specifically, we introduce games that test for $L$-perfect bipartite graphs, general hypergraphs, fractional matchings. Our definitions come from the fact these are classical property tests corresponding matching conditions. use existence strategies to define versions Finally, provide characterizations when exhibit extended properties: - For matchings, give a complete combinatorial...
We consider a communication method, where the sender encodes n classical bits into 1 qubit and sends it to receiver who performs certain measurement depending on which of initial must be recovered. This procedure is called (n,1,p) quantum random access code (QRAC) p > 1/2 its success probability. It known that (2,1,0.85) (3,1,0.79) QRACs (with no counterparts) exist (4,1,p) QRAC with not possible. extend this model shared randomness (SR) accessible both parties. Then SR exists for any 0....
We study zero-error entanglement-assisted source-channel coding (communication in the presence of side information). Adapting a technique Beigi, we show that such requires existence set vectors satisfying orthogonality conditions related to suitably defined graphs G and H. Such exist if only ϑ(G̅) ≤ ϑ(H̅), where ϑ represents Lovász number. also obtain similar inequalities for Schrijver <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup>...
We introduce two generalizations of Kochen-Specker (KS) sets: projective KS sets and generalized sets. then use to characterize all graphs for which the chromatic number is strictly larger than quantum number. Here, defined via a nonlocal game based on graph coloring. further show that from any with separation between these quantities, one can construct classical channel entanglement assistance increases one-shot zero-error capacity. As an example, we exhibit new family channels exponential increase.
The first cases of COVID-19 caused by the SARS-CoV-2 virus were reported in China December 2019. disease has since spread globally. Many countries have instated measures to slow virus. Information about a country can inform gradual reopening and help avoid second wave infections. Our study focuses on Denmark, which is opening up when this performed (end-May 2020) after lockdown mid-March.We perform phylogenetic analysis 742 publicly available Danish genome sequences put them into context...
Suppose we can apply a given 2-qubit Hamiltonian H to any (ordered) pair of qubits.We say is n-universal if it be used approximate unitary operation onn qubits. While well known that almost 2-universal(Deutsch, Barenco, Ekert 1995; Lloyd 1995), an explicit characterization the set ofnon-universal Hamiltonians has been elusive. Our main result completecharacterization 2-non-universal Hamiltonians. In particular, there are threeways fail universal: (1) shares eigenvectorwith gate swaps two...
The main purpose of this work is to collect some interesting facts related quantum graph coloring.We consider the orthogonality three-dimensional vectors with entries from set {-1, 0, 1}.If we ignore overall sign vectors, yields a on thirteen vertices, which denote by G13.It turns out that G13 (or obtained adding an apex vertex) smallest known example exhibits separations between several parameters.We are particularly interested in using separate parameters their classical counterparts.We...