ORCID Profile
0000-0003-4561-5124
Current Organisations
National University of Singapore
,
University of Oxford
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Publisher: American Physical Society (APS)
Date: 11-09-2013
Publisher: IOP Publishing
Date: 18-04-2016
Publisher: American Physical Society (APS)
Date: 05-09-2013
Publisher: Springer Science and Business Media LLC
Date: 09-2014
Publisher: The Royal Society
Date: 03-10-2012
Abstract: Physical systems are often simulated using a stochastic computation where different final states result from identical initial states. Here, we derive the minimum energy cost of simulating a data sequence of a general physical system by stochastic computation. We show that the cost is proportional to the difference between two information-theoretic measures of complexity of the data—the statistical complexity and the predictive information . We derive the difference as the amount of information erased during the computation. Finally, we illustrate the physics of information by implementing the stochastic computation as a Gedanken experiment with a Szilard-type engine. The results create a new link between thermodynamics, information theory and complexity.
Publisher: Springer Science and Business Media LLC
Date: 16-10-2019
DOI: 10.1038/S41467-019-12643-2
Abstract: Modern computation relies crucially on modular architectures, breaking a complex algorithm into self-contained subroutines. A client can then call upon a remote server to implement parts of the computation independently via an application programming interface (API). Present APIs relay only classical information. Here we implement a quantum API that enables a client to estimate the absolute value of the trace of a server-provided unitary operation $$U$$ U . We demonstrate that the algorithm functions correctly irrespective of what unitary $$U$$ U the server implements or how the server specifically realizes $$U$$ U . Our experiment involves pioneering techniques to coherently swap qubits encoded within the motional states of a trapped $${}^{171}{{\\rm{Yb}}}^{+}\\,$$ 171 Yb + ion, controlled on its hyperfine state. This constitutes the first demonstration of modular computation in the quantum regime, providing a step towards scalable, parallelization of quantum computation.
Publisher: IOP Publishing
Date: 12-10-2017
Publisher: American Physical Society (APS)
Date: 13-11-2014
Publisher: Springer Science and Business Media LLC
Date: 18-05-2020
Publisher: American Physical Society (APS)
Date: 23-05-2013
Publisher: American Physical Society (APS)
Date: 07-11-2016
Publisher: American Physical Society (APS)
Date: 24-04-2017
Publisher: Springer Science and Business Media LLC
Date: 05-08-2012
DOI: 10.1038/NPHYS2376
Publisher: Springer Science and Business Media LLC
Date: 05-08-2012
DOI: 10.1038/NPHYS2377
Publisher: American Physical Society (APS)
Date: 18-07-2018
Publisher: IOP Publishing
Date: 05-01-2018
Publisher: Springer Science and Business Media LLC
Date: 05-2012
DOI: 10.1038/NCOMMS1809
Abstract: The observation that concepts from quantum information has generated many alternative indicators of quantum phase transitions hints that quantum phase transitions possess operational significance with respect to the processing of quantum information. Yet, studies on whether such transitions lead to quantum phases that differ in their capacity to process information remain limited. Here we show that there exist quantum phase transitions that cause a distinct qualitative change in our ability to simulate certain quantum systems under perturbation of an external field by local operations and classical communication. In particular, we show that in certain quantum phases of the XY model, adiabatic perturbations of the external magnetic field can be simulated by local spin operations, whereas the resulting effect within other phases results in coherent non-local interactions. We discuss the potential implications to adiabatic quantum computation, where a computational advantage exists only when adiabatic perturbation results in coherent multi-body interactions.
Publisher: The Royal Society
Date: 13-10-2012
Abstract: We construct a quantumness witness following the work of Alicki & van Ryn (AvR). We reformulate the AvR test by defining it for quantum states rather than for observables. This allows us to identify the necessary quantities and resources to detect quantumness for any given system. The first quantity turns out to be the purity of the system. When applying the witness to a system with even moderate mixedness, the protocol is unable to reveal any quantumness. We then show that having many copies of the system leads the witness to reveal quantumness. This seems contrary to the Bohr correspondence, which asserts that, in the large-number limit, quantum systems become classical, whereas the witness shows quantumness when several non-quantum systems, as determined by the witness, are considered together. However, the resources required to detect the quantumness increase dramatically with the number of systems. We apply the quantumness witness for systems that are highly mixed but in the large-number limit that resembles nuclear magnetic resonance (NMR) systems. We make several conclusions about detecting quantumness in NMR-like systems.
Publisher: AIP
Date: 2011
DOI: 10.1063/1.3635845
Publisher: IEEE
Date: 08-2011
Publisher: AIP Publishing LLC
Date: 2014
DOI: 10.1063/1.4903110
Publisher: American Physical Society (APS)
Date: 03-05-2016
Publisher: American Physical Society (APS)
Date: 22-02-2010
Publisher: OSA
Date: 2014
Publisher: American Physical Society (APS)
Date: 22-04-2016
Publisher: Springer Science and Business Media LLC
Date: 10-02-2017
DOI: 10.1038/S41534-016-0001-3
Abstract: All natural things process and transform information. They receive environmental information as input, and transform it into appropriate output responses. Much of science is dedicated to building models of such systems—algorithmic abstractions of their input–output behavior that allow us to simulate how such systems can behave in the future, conditioned on what has transpired in the past. Here, we show that classical models cannot avoid inefficiency—storing past information that is unnecessary for correct future simulation. We construct quantum models that mitigate this waste, whenever it is physically possible to do so. This suggests that the complexity of general input–output processes depends fundamentally on what sort of information theory we use to describe them.
Publisher: Elsevier BV
Date: 06-2018
Publisher: IEEE
Date: 05-2013
Publisher: Springer Science and Business Media LLC
Date: 27-03-2012
DOI: 10.1038/NCOMMS1761
Abstract: Mathematical models are an essential component of quantitative science. They generate predictions about the future, based on information available in the present. In the spirit of simpler is better should two models make identical predictions, the one that requires less input is preferred. Yet, for almost all stochastic processes, even the provably optimal classical models waste information. The amount of input information they demand exceeds the amount of predictive information they output. Here we show how to systematically construct quantum models that break this classical bound, and that the system of minimal entropy that simulates such processes must necessarily feature quantum dynamics. This indicates that many observed phenomena could be significantly simpler than classically possible should quantum effects be involved.
Publisher: American Physical Society (APS)
Date: 12-11-2018
Publisher: Springer Science and Business Media LLC
Date: 24-11-2015
DOI: 10.1038/NPJQI.2015.7
Abstract: In general relativity, closed timelike curves can break causality with remarkable and unsettling consequences. At the classical level, they induce causal paradoxes disturbing enough to motivate conjectures that explicitly prevent their existence. At the quantum level such problems can be resolved through the Deutschian formalism, however this induces radical benefits—from cloning unknown quantum states to solving problems intractable to quantum computers. Instinctively, one expects these benefits to vanish if causality is respected. Here we show that in harnessing entanglement, we can efficiently solve NP-complete problems and clone arbitrary quantum states—even when all time-travelling systems are completely isolated from the past. Thus, the many defining benefits of Deutschian closed timelike curves can still be harnessed, even when causality is preserved. Our results unveil a subtle interplay between entanglement and general relativity, and significantly improve the potential of probing the radical effects that may exist at the interface between relativity and quantum theory.
Publisher: IEEE
Date: 06-2013
Publisher: IOP Publishing
Date: 20-06-2011
Publisher: American Physical Society (APS)
Date: 03-06-2014
Publisher: American Physical Society (APS)
Date: 02-2016
Publisher: IOP Publishing
Date: 11-01-2016
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for vlatko vedral.