Chip-based array of near-identical, pure, heralded single-photon sources

Spring, Justin B.; Mennea, Paolo L.; Metcalf, Benjamin J.; Humphreys, Peter C.; Gates, James C.; Rogers, Helen; Söller, Christoph; Smith, Brian J.; Kolthammer, W. Steven; Smith, Peter G. R.; Walmsley, Ian A.

doi:10.1364/optica.4.000090

Cited by 104 publications

(107 citation statements)

References 46 publications

Supporting

Mentioning

104

Contrasting

Unclassified

Order By: Relevance

“…1 and has been experimentally realized to some extent for near-identical, pure, heralded SPEs [51]. We estimate the source separation distance d after the array is subjected to a general homogeneous FIG.…”

Section: Generator Of Translationsmentioning

confidence: 99%

Quantum metrology of spatial deformation using arrays of classical and quantum light emitters

Sidhu

Kok

2017

Phys. Rev. A

View full text Add to dashboard Cite

We introduce spatial deformations to an array of light sources and study how the estimation precision of the interspacing distance d changes with the sources of light used. The quantum Fisher information (QFI) is used as the figure of merit in this work to quantify the amount of information we have on the estimation parameter. We derive the generator of translationsĜ in d due to an arbitrary homogeneous deformation applied to the array. We show how the variance of the generator can be used to easily consider how different deformations and light sources can effect the estimation precision. The single-parameter estimation problem is applied to the array, and we report on the optimal state that maximizes the QFI for d. Contrary to what may have been expected, the higher average mode occupancies of the classical states performs better in estimating d when compared with single photon emitters (SPEs). The optimal entangled state is constructed from the eigenvectors of the generator and found to outperform all these states. We also find the existence of multiple optimal estimators for the measurement of d. Our results find applications in evaluating stresses and strains, fracture prevention in materials expressing great sensitivities to deformations, and selecting frequency distinguished quantum sources from an array of reference sources.

show abstract

Section: Generator Of Translationsmentioning

confidence: 99%

Quantum metrology of spatial deformation using arrays of classical and quantum light emitters

Sidhu

Kok

2017

Phys. Rev. A

View full text Add to dashboard Cite

show abstract

“…The advent of integrated quantum photonics 10 has enabled large, complex, stable and programmable optical circuitry 11,12 , while recent advances in photon generation [13][14][15] and detection 16,17 have also been impressive. The possibility to generate many photons, evolve them under a large linear optical unitary transformation, then detect them, seems feasible, so the role of a boson sampling machine as a rudimentary but legitimate computing device is particularly appealing.…”

mentioning

confidence: 99%

Classical boson sampling algorithms with superior performance to near-term experiments

et al. 2017

View full text Add to dashboard Cite

It is predicted that quantum computers will dramatically outperform their conventional counterparts. However, largescale universal quantum computers are yet to be built. Boson sampling 1 is a rudimentary quantum algorithm tailored to the platform of linear optics, which has sparked interest as a rapid way to demonstrate such quantum supremacy 2-6 . Photon statistics are governed by intractable matrix functions, which suggests that sampling from the distribution obtained by injecting photons into a linear optical network could be solved more quickly by a photonic experiment than by a classical computer. The apparently low resource requirements for large boson sampling experiments have raised expectations of a near-term demonstration of quantum supremacy by boson sampling 7,8 . Here we present classical boson sampling algorithms and theoretical analyses of prospects for scaling boson sampling experiments, showing that near-term quantum supremacy via boson sampling is unlikely. Our classical algorithm, based on Metropolised independence sampling, allowed the boson sampling problem to be solved for 30 photons with standard computing hardware. Compared to current experiments, a demonstration of quantum supremacy over a successful implementation of these classical methods on a supercomputer would require the number of photons and experimental components to increase by orders of magnitude, while tackling exponentially scaling photon loss.It is believed that new types of computing machines will be constructed to exploit quantum mechanics for an exponential speed advantage in solving certain problems compared with classical computers 9 . Recent large state and private investments in developing quantum technologies have increased interest in this challenge. However, it is not yet experimentally proven that a large computationally useful quantum system can be assembled, and such a task is highly non-trivial given the challenge of overcoming the effects of errors in these systems.Boson sampling is a simple task which is native to linear optics and has captured the imagination of quantum scientists because it seems possible that the anticipated supremacy of quantum machines could be demonstrated by a near-term experiment. The advent of integrated quantum photonics 10 has enabled large, complex, stable and programmable optical circuitry 11,12 , while recent advances in photon generation [13][14][15] and detection 16,17 have also been impressive. The possibility to generate many photons, evolve them under a large linear optical unitary transformation, then detect them, seems feasible, so the role of a boson sampling machine as a rudimentary but legitimate computing device is particularly appealing. Compared to a universal digital quantum computer, the resources required for experimental boson sampling appear much less demanding. This approach of designing quantum algorithms to demonstrate computational supremacy with nearterm experimental capabilities has inspired a raft of proposals suited to different hardware platforms [18]...

show abstract

“…We confirm that this is indeed an anti-bunched state, with the fidelity of 95.0%. Furthermore, this measurement permits us to get information about the spectral overlap of the pair of photons, since the observed correlations exhibit a generalized form of Hong-Ou-Mandel interference [27][28][29], see Sec. 1 of the supplementary material for details.…”

mentioning

confidence: 99%

Scalable on-chip quantum state tomography

Titchener

Gräfe

Heilmann

et al. 2016

Frontiers in Optics 2016

View full text Add to dashboard Cite

Quantum information systems are on a path to vastly exceed the complexity of any classical device. The number of entangled qubits in quantum devices is rapidly increasing [1][2][3] and the information required to fully describe these systems scales exponentially with qubit number [4]. This scaling is the key benefit of quantum systems, however it also presents a severe challenge. To characterize such systems typically requires an exponentially long sequence of different measurements [5], becoming highly resource demanding for large numbers of qubits [6]. Here we propose a novel and scalable method to characterize quantum systems, where the complexity of the measurement process only scales linearly with the number of qubits. We experimentally demonstrate an integrated photonic chip capable of measuring two-and three-photon quantum states with reconstruction fidelity of 99.67%. arXiv:1704.03595v[physics.optics] 12 Apr 2017The standard way to characterize a quantum system is known as quantum state tomography [5,7]. It involves measuring expectation values of a complete set of observables and using these to reconstruct the system's density matrix [8][9][10][11][12][13]. To characterize an N -qubit state, 2 2N different observables are measured [8], thus the measurement apparatus must be reconfigured exponentially many times, which is impractical for large states. Furthermore many of the expectation values measured will be vanishingly small, and thus contribute little useful information. Finally, even if all the measurements can be completed, the task of reconstructing the density matrix from measurement data becomes computationally challenging for high qubit-number states [6].New approaches to quantum state tomography are being developed in an effort to increase its practicality and efficiency. Some approaches seek to avoid unnecessary measurements by assuming that the system is in particular low rank states, such as sparse states [14,15] measurements have increased error robustness relative to using only local qubit measurements, and thus can be completed in less time [19]. The computational burden of inverting large data sets to find the density matrix is reduced with simple real-time optimization algorithms in self guided tomography, or can be completely avoided with systems for direct projection of density matrix parameters [20][21][22]. However all these approaches rely on a common measurement paradigm, whereby different characteristics of a system are measured sequentially, thus they become exponentially complex to implement as the number of parameters in the density matrix scales exponentially with qubit number.Here we present a quantum tomography method with complexity that scales linearly with qubit number. This is achieved by leveraging quantum systems' greatest strength, the simultaneous occupation of exponentially many states, in the measurement process. Instead of preforming a sequence of different measurements on the state, we design a single static measurement system [Fig. 7(a)] that preforms...

show abstract

Chip-based array of near-identical, pure, heralded single-photon sources

Cited by 104 publications

References 46 publications

Quantum metrology of spatial deformation using arrays of classical and quantum light emitters

Quantum metrology of spatial deformation using arrays of classical and quantum light emitters

Classical boson sampling algorithms with superior performance to near-term experiments

Scalable on-chip quantum state tomography

Contact Info

Product

Resources

About