QI team
  • Home
  • Research
    • Overview
    • Recent publications
    • Open positions
  • Members
    • The team
    • Associate members
  • Events
  • Contact

Quantum certification and benchmarking
J. Eisert, D. Hangleiter, N. Walk, I. Roth, D. Markham, R. Parekh, U. Chabaud, E. Kashefi
Concomitant with the rapid development of quantum technologies, challenging demands arise concerning the certification and characterization of devices. The promises of the field can only be achieved if stringent levels of precision of components can be reached and their functioning guaranteed. This Expert Recommendation provides a brief overview of the known characterization methods of certification, benchmarking, and tomographic recovery of quantum states and processes, as well as their applications in quantum computing, simulation, and communication. More details here. 
Picture

The stellar representation of non-Gaussian quantum states
U. Chabaud, D. Markham, F. Grosshans
This article uses the so-called stellar formalism to represent the non-Gaussian properties of single-mode quantum states by the distribution of the zeros of their Husimi Q-function in phase-space. An infinite hierarchy of single-mode states based on the number of zeros of the Husimi Q-function, the stellar hierarchy, is derived, along with an operational characterisation of the states in this hierarchy with the minimal number of single-photon additions needed to engineer them. More details here. 
Picture

Building trust for continuous variable quantum states
U. Chabaud, T. Douce, F. Grosshans, E. Kashefi, D. Markham
This article studies heterodyne quantum state tomography, a reliable method for continuous variable quantum state certification which directly yields the elements of the density matrix of the state considered and analytical confidence intervals, using heterodyne detection. This method neither needs mathematical reconstruction of the data, nor discrete binning of the sample space, and uses a single Gaussian measurement setting. More details here. 
Picture

A comonadic view of simulation and quantum resources
S. Abramsky, R. Soares Barbosa, M. Karvonen, S. Mansfield
This article 
studies simulation and quantum resources in the setting of the sheaf-theoretic approach to contextuality and non-locality. Resources are viewed behaviourally, as empirical models. More details here.
Picture

Semi-device-independent quantum money with coherent states
M. Bozzio, E. Diamanti, F. Grosshans
This article 
provides a security proof for semi-device-independent quantum money with classical verification, involving an honest bank, a dishonest client and a potentially untrusted terminal. The analysis uses semidefinite programming in the coherent state framework and aims at simultaneously optimizing over the noise and losses introduced by a dishonest party. More details here.
Picture

Optimal quantum-programmable projective measurement with linear optics
​U. Chabaud, E. Diamanti, D. Markham, E. Kashefi, A. Joux
This article presents a scheme for a universal device which can be programmed by quantum states to perform optimally a chosen projective measurement, and its implementation in linear optics. More details here.
Picture

Tsirelson’s bound and Landauer’s principle in a single-system game
​L. Henaut, L. Catani, D. E. Browne, S. Mansfield, A. Pappa
This article introduces a simple single-system game inspired by the CHSH game which highlights a connection between the reversibility in fundamental operations embodied by Landauer’s principle and Tsirelson’s bound that arises from the restricted physics of a unitarily evolving single-qubit system. More details here.
Picture

Distributing Graph States Over Arbitrary Quantum Networks
C. Meignant, D. Markham, F. Grosshans
This work studies the distribution, or routing, of entangled states over fixed, but arbitrary, physical networks. It introduces two protocols to distribute respectively Greenberger–Horne–Zeilinger (GHZ) states and arbitrary graph states over arbitrary quantum networks. The GHZ states distribution protocol takes a single step and is optimal in terms of the number of Bell pairs used; the graph state distribution protocol uses at most twice as many Bell pairs and steps than the optimal routing protocol for the worst case scenario. More details here.
Picture

Quantum secret sharing using squeezing and almost any passive interferometer
F. Arzani, G. Ferrini, F. Grosshans, D. Markham
This article considers the sharing of quantum secret states using continuous variable systems. Specifically it introduces an encoding procedure where the secret mode is mixed with several ancillary squeezed modes through a passive interferometer. It is shown that if the interferometer is chosen uniformly at random, the probability that it may not be used to implement a quantum secret sharing protocol is zero. More details here.
Picture

Quantum Advantage from Sequential-Transformation Contextuality
​S. Mansfield, E. Kashefi
This article introduces a notion of contextuality for transformations in sequential contexts, distinct from the Bell- Kochen-Specker and Spekkens notions of contextuality. Within a transformation-based model for quantum computation we show that strong sequential-transformation contextuality is necessary and sufficient for deterministic computation of nonlinear functions if classical components are restricted to mod2 linearity and matching constraints apply to any underlying ontology. More details here.
Picture

Quantum superiority for verifying NP-complete problems with linear optics
​J. M. Arrazola, E. Diamanti, I. Kerenidis
This article studies a quantum superiority procedure for verifying NP-complete problems with linear optics. It introduces a simple protocol using single photon states and a few operations. More details here.
Photo

Verification of quantum computing: An overview of existing approaches
​A. Gheorghiu, T. Kapourniotis, E. Kashefi
This article reviews the most significant approaches to quantum verification and compare them in terms of structure, complexity and required resources. More details here.
Photo

Efficient quantum pseudo randomness with simple graph states
R. Mezher, J. Ghalbouni, J. Dgheim, D. Markham
​
This article shows how to produce an
ϵ-approximate-t-design on n qubits by repeating a measurement based scheme an efficient number of times, on a simple graph state, with measurements at fixed angles and no feed-forward corrections. More details here.
Photo

Experimental detection of steerability in Bell local states with two measurement settings 
A. Orieux, M. Kaplan, V. Venuti, T. Pramanik, I. Zaquine, E. Diamanti
​This article numerically and experimentally investigate a steering inequality for generalized Werner states and successfully detect steerability in a wide range of two-photon polarization-entangled Bell local states generated by a parametric down-conversion source. . More details here.
Photo

Continuous-Variable sampling from photon-added or photon-subtracted squeezed states
​U. Chabaud, T. Douce, D. Markham, P. van Look, E. Kashefi, G. Ferrini
This article defines a model of quantum sampler in continuous variable and proves that it is hard to sample exactly classically unless the Polynomial Hierarchy collapses to the third level. More details here.
Photo

The quantum Cut-and-Choose technique and quantum two-party computation
​E. Kashefi, L. Music, P. Wallden
This article introduces a Quantum Computation Cut-and-Choose (QC-CC) technique which is a generalisation of the classical Cut-and-Choose in order to build quantum protocols secure against quantum covert adversaries. More details here.
Photo

Experimental investigation of practical unforgeable quantum money
​M. Bozzio, A. Odieux, L. Trigo Vidarte, I. Zaquine, I. Kerenidis, E. Diamanti
This article shows experimental implementation of a quantum money protocol relying on classical verification that rigorously satises the security condition for unforgeability. The system exploits polarization encoding of weak coherent states of light and operates under conditions that ensure compatibility with state-of-the-art quantum memories. More details here.
Photo

Raman-tailored photonics crystal fiber for telecom band photon-pair generation
​M. Cordier, A. Orieux, R. Gabet, T. Harlé, N. Dubreuil, E. Diamanti, P. Delaye, I. Zaquine
This article reports on the experimental characterization of a novel nonlinear liquid-filled hollow-core photonic crystal fiber for the generation of photon pairs at a telecommunication wavelength through spontaneous four-wave mixing (SFWM). More details here.
Photo

Efficient quantum communications with multiplexed coherent state fingerprints
N. Kumar, I. Kerenidis, E. Diamanti
This article provide the first example of a communication model and a distributed task, for which there exists a realistic quantum protocol which is asymptotically more efficient than any classical protocol, both in the communication and the information resources. More details here.
Photo

Minimum quantum resources for strong non-locality
S. Abramsky, R. Soares Barbosa, G. Carù, N. de Silva, K. Kishida, S. Mansfield
This article analyses the minimum quantum resources needed to realise strong non-locality. More details here.
Photo

Powered by Create your own unique website with customizable templates.
  • Home
  • Research
    • Overview
    • Recent publications
    • Open positions
  • Members
    • The team
    • Associate members
  • Events
  • Contact