Experimental High-Dimensional Quantum Teleportation

Physical Review Letters, Journal Year: 2020, Volume and Issue: 125(23)

Published: Dec. 2, 2020

Quantum teleportation provides a way to transmit unknown quantum states from one location another. In the world, multilevel systems which enable high-dimensional are more prevalent. Therefore, completely rebuild of single particle remotely, needs teleport (high-dimensional) states. Here, we demonstrate in three-dimensional six-photon system. We exploit spatial mode photon as system, use two auxiliary entangled photons realize deterministic Bell state measurement. The fidelity process matrix is F=0.596\pm0.037. Through this matrix, can prove that our both nonclassical and genuine three dimensional. Our work paves complex remotely construct networks.

Language: Английский

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Efficient Generation of High-Dimensional Entanglement through Multipath Down-Conversion

Physical Review Letters, Journal Year: 2020, Volume and Issue: 125(9)

Published: Aug. 28, 2020

High-dimensional entanglement promises to greatly enhance the performance of quantum communication and enable advantages unreachable by qubit entanglement. One great challenges, however, is reliable production, distribution, local certification high-dimensional sources In this Letter, we present an optical setup capable producing states with exceptionally high level scalability, control, quality that, together novel techniques, achieve highest amount recorded so far. We showcase in 32-spatial dimensions record fidelity maximally entangled state (F=0.933±0.001) introduce measurement efficient schemes certify formation (E_{oF}=3.728±0.006). Combined existing multicore fiber technology, our results will lay a solid foundation for construction networks.

Language: Английский

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Genuine High-Dimensional Quantum Steering

Physical Review Letters, Journal Year: 2021, Volume and Issue: 126(20)

Published: May 20, 2021

High-dimensional quantum entanglement can give rise to stronger forms of nonlocal correlations compared qubit systems, offering significant advantages for information processing. Certifying these correlations, however, remains an important challenge, in particular experimental setting. Here we theoretically formalise and experimentally demonstrate a notion genuine high-dimensional steering. We show that entanglement, as quantified by the Schmidt number, lead form steering, provably impossible obtain via lower dimensions. Exploiting connection between steering incompatibility measurements, derive simple two-setting inequalities, violation which guarantees presence hence certifies bound on number one-sided device-independent report inequalities using macro-pixel photon-pair certifying In particular, entangled state dimension $d=31$, our data minimum $n=15$.

Language: Английский

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Quantum Key Distribution Overcoming Extreme Noise: Simultaneous Subspace Coding Using High-Dimensional Entanglement

Physical Review Applied, Journal Year: 2021, Volume and Issue: 15(3)

Published: March 1, 2021

High-dimensional entanglement promises to increase the information capacity of photons and is now routinely generated, exploiting spatiotemporal degrees freedom single photons. A curious feature these systems possibility certifying despite strong noise in data. We show that it also possible exploit this noisy high-dimensional for quantum key distribution by introducing a protocol uses multiple subspaces system simultaneously. Our can be used establish secret even extremely experimental conditions, where qubit protocols fail. To that, we analyze performance our models apply two most commonly sources entanglement: time bins spatial modes.

Language: Английский

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Entanglement Quantification in Atomic Ensembles

Physical Review Letters, Journal Year: 2021, Volume and Issue: 127(1)

Published: June 29, 2021

Entanglement measures quantify nonclassical correlations present in a quantum system, but can be extremely difficult to calculate, even more so, when information on its state is limited. Here, we consider broad families of entanglement criteria that are based variances arbitrary operators and analytically derive the lower bounds these provide for two relevant measures: best separable approximation generalized robustness. This yields practical method quantifying realistic experimental situations, particular, only few measurements simple observables available. As concrete application this method, bipartite multipartite spin-squeezed Bose-Einstein condensates ∼500 atoms, by bounding robustness from first second moments collective spin operator.

Language: Английский

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Measuring dimensionality and purity of high-dimensional entangled states

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: Aug. 27, 2021

Abstract High-dimensional entangled states are promising candidates for increasing the security and encoding capacity of quantum systems. While it is possible to witness set bounds entanglement, precisely quantifying dimensionality purity in a fast accurate manner remains an open challenge. Here, we report approach that simultaneously returns high-dimensional by simple projective measurements. We show outcome conditional measurement visibility scales monotonically with state purity, allowing quantitative measurements general photonic illustrate our method using two separate bases, orbital angular momentum pixels quantify variety definitions over wide range noise levels, highlighting its usefulness practical situations. Importantly, number needed scale linearly dimensions, reducing data acquisition time significantly. Our technique provides simple, direct approach.

Language: Английский

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Quantum key distribution rates from semidefinite programming

Quantum, Journal Year: 2023, Volume and Issue: 7, P. 1019 - 1019

Published: May 24, 2023

Computing the key rate in quantum distribution (QKD) protocols is a long standing challenge. Analytical methods are limited to handful of with highly symmetric measurement bases. Numerical can handle arbitrary bases, but either use min-entropy, which gives loose lower bound von Neumann entropy, or rely on cumbersome dedicated algorithms. Based recently discovered semidefinite programming (SDP) hierarchy converging conditional used for computing asymptotic rates device independent case, we introduce an SDP that converges secret case characterised devices. The resulting algorithm efficient, easy implement and use. We illustrate its performance by recovering known bounds extending high-dimensional QKD previously intractable cases. also it reanalyse experimental data demonstrate how higher be achieved when full statistics taken into account.

Language: Английский

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Processing Entangled Photons in High Dimensions with a Programmable Light Converter

Physical Review Applied, Journal Year: 2022, Volume and Issue: 18(1)

Published: July 26, 2022

High-dimensional entanglement offers a variety of advantages for both fundamental and applied applications in quantum information science. A central building block such is programmable processor entangled states, which crucial the certification, manipulation, distribution high-dimensional entanglement. The leading technology processing photons integrated multiport interferometers. However, devices are incompatible with structured light their scaling challenging. Here, we unlock these limitations by demonstrating reconfigurable high dimensions that based on multiplane conversion (MPLC), has recently been developed multiplexing hundreds spatial modes classical communication. We use our MPLC platform to certify three-dimensional two mutually unbiased bases, perform 400 arbitrary random transformations photons, convert mode basis distribution.

Language: Английский

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Entangled ripples and twists of light: radial and azimuthal Laguerre–Gaussian mode entanglement

Journal of Optics, Journal Year: 2021, Volume and Issue: 23(10), P. 104001 - 104001

Published: Aug. 25, 2021

It is well known that photons can carry a spatial structure akin to "twisted" or "rippled" wavefront. Such structured light fields have sparked significant interest in both classical and quantum physics, with applications ranging from dense communications light-matter interaction. Harnessing the full advantage of transverse photonic encoding using Laguerre-Gaussian (LG) basis domain requires control over azimuthal (twisted) radial (rippled) components photons. However, precise measurement degree-of-freedom has proven be experimentally challenging primarily due its amplitude structure. Here we demonstrate generation certification full-field entanglement between pairs generated by spontaneous parametric down-conversion telecom regime. By precisely tuning optical system parameters for state collection, adopting recently developed techniques mode measurement, are able certify fidelities up 85% dimensionalities 26 43-dimensional LG space. Furthermore, study two-photon correlations 9 groups, demonstrating correlation related group order inter-modal cross-talk. In addition, show how noise-robustness high-dimensional significantly increased measurements multiple mutually unbiased bases. Our work demonstrates potential offered field enhancing technologies information processing communication.

Language: Английский

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Remotely Establishing Polarization Entanglement Over Noisy Polarization Channels

Physical Review Applied, Journal Year: 2022, Volume and Issue: 17(3)

Published: March 3, 2022

The faithful distribution of entanglement over noisy channels is a vital prerequisite for many quantum technological applications. Quantum information can be encoded in different degrees freedom (DOF) photons, where each encoding comes with its own advantages and disadvantages respect to noise resilience practicality manipulation. In this work, we experimentally implement deterministic purification protocol that allows us faithfully distribute one DOF channel then remotely transfer it another particular, robust energy-time polarization at the communicating parties. obtained state independent during reaches fidelities Bell up $97.6\mathrm{%}$. Our scheme enables efficient presence arbitrary noise, which relevant future large-scale networks.

Language: Английский

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