Experimental high-dimensional two-photon entanglement and violations of generalized Bell inequalities

Dada, Adetunmise C.; Leach, Jonathan; Buller, Gerald S.; Padgett, Miles J.; Andersson, Erika

doi:10.1038/nphys1996

Cited by 634 publications

(545 citation statements)

References 31 publications

Supporting

Mentioning

535

Contrasting

Unclassified

Order By: Relevance

“…If la0, such modes exhibit a vortex along the beam axis and show a ring-shaped intensity structure; consequently they are also called 'doughnut modes'. LG modes can be used to transmit more classical information [5][6][7][8][9] or realize a higher-dimensional quantum state 11,21,22 . To access the encoded information efficiently a MS was developed 18,19 , which consists of two freeform refractive optical elements that convert the OAM content of an incident light field to lateral positions of the output.…”

Section: Generation Of Oam Modes With a Ms In Reversementioning

confidence: 99%

Interface between path and orbital angular momentum entanglement for high-dimensional photonic quantum information

et al. 2014

Self Cite

View full text Add to dashboard Cite

Photonics has become a mature field of quantum information science, where integrated optical circuits offer a way to scale the complexity of the set-up as well as the dimensionality of the quantum state. On photonic chips, paths are the natural way to encode information. To distribute those high-dimensional quantum states over large distances, transverse spatial modes, like orbital angular momentum possessing Laguerre Gauss modes, are favourable as flying information carriers. Here we demonstrate a quantum interface between these two vibrant photonic fields. We create three-dimensional path entanglement between two photons in a nonlinear crystal and use a mode sorter as the quantum interface to transfer the entanglement to the orbital angular momentum degree of freedom. Thus our results show a flexible way to create high-dimensional spatial mode entanglement. Moreover, they pave the way to implement broad complex quantum networks where high-dimensionally entangled states could be distributed over distant photonic chips.

show abstract

Section: Generation Of Oam Modes With a Ms In Reversementioning

confidence: 99%

Interface between path and orbital angular momentum entanglement for high-dimensional photonic quantum information

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…An LG beam with azimuthal mode index ℓ carries an orbital angular momentum (OAM) of ℓ per photon [2,3]. One can, in principle, use the OAM modes of light to implement a higher dimensional state space for a single photon [4,5]. A pair of photons entangled in their OAM degree of freedom can be generated by spontaneous parametric down conversion (SPDC).…”

Section: Introductionmentioning

confidence: 99%

Orbital-angular-momentum entanglement in turbulence

et al. 2013

View full text Add to dashboard Cite

The turbulence induced decay of orbital angular momentum (OAM) entanglement between two photons is investigated numerically and experimentally. To compare our results with previous work, we simulate the turbulent atmosphere with a single phase screen based on the Kolmogorov theory of turbulence. We consider two different scenarios: in the first only one of the two photons propagates through turbulence, and in the second both photons propagate through uncorrelated turbulence. Comparing the entanglement evolution for different OAM values, we found the entanglement to be more robust in turbulence for higher OAM values. We derive an empirical formula for the distance scale at which entanglement decays in term of the scale parameters and the OAM value.

show abstract

“…There, different multilevel degrees of freedom, such as spatial modes (13), time-energy (14), path (15,16), as well as continuous variables (17,18), have been used. Entanglement of spatial modes of photons has especially attracted much attention in recent years (19)(20)(21)(22)(23)(24)(25)(26)(27)(28), because it is readily available from optical nonlinear crystals and the number of involved modes of the entanglement can be very high (29).…”

mentioning

confidence: 99%

Generation and confirmation of a (100 × 100)-dimensional entangled quantum system

Krenn

Huber

Fickler

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

305

254

View full text Add to dashboard Cite

Entangled quantum systems have properties that have fundamentally overthrown the classical worldview. Increasing the complexity of entangled states by expanding their dimensionality allows the implementation of novel fundamental tests of nature, and moreover also enables genuinely new protocols for quantum information processing. Here we present the creation of a (100 × 100)-dimensional entangled quantum system, using spatial modes of photons. For its verification we develop a novel nonlinear criterion which infers entanglement dimensionality of a global state by using only information about its subspace correlations. This allows very practical experimental implementation as well as highly efficient extraction of entanglement dimensionality information. Applications in quantum cryptography and other protocols are very promising.photonic spatial modes | quantum optics | Schmidt rank | entanglement witness Q uantum entanglement of distant particles leads to correlations that cannot be explained in a local realistic way (1-3). To obtain a deeper understanding of entanglement itself, as well as its application in various quantum information tasks, increasing the complexity of entangled systems is important. Essentially, this can be done in two ways. The first method is to increase the number of particles involved in the entanglement (4). The alternative method is to increase the entanglement dimensionality of a system.Here we focus on the latter one, namely on the dimension of the entanglement. The text is structured as follows. After a short review of properties and previous experiments, we present a unique method to verify high-dimensional entanglement. Then we show how we experimentally create our high-dimensional two-photon entangled state. We analyze this state with our method and verify a 100 × 100-dimensional entangled quantum system. We conclude with a short outlook to potential future investigations.High-dimensional entanglement provides a higher information density than conventional two-dimensional (qubit) entangled states, which has important advantages in quantum communication. First, it can be used to increase the channel capacity via superdense coding (5). Second, high-dimensional entanglement enables the implementation of quantum communication tasks in regimes where mere qubit entanglement does not suffice. This involves situations with a high level of noise from the environment (6, 7), or quantum cryptographic systems where an eavesdropper has manipulated the random number generator involved (8). Moreover, the entangled dimensions of the whole Hilbert space also play a very interesting role in quantum computation: high-dimensional systems can be used to simplify the implementation of quantum logic (9). Furthermore, it has been found recently (10) that any continuous measure of entanglement (such as concurrence, entanglement of formation, or negativity) can be very small, while the quantum system still permits an exponential computation speedup over classical machines. This is not the case for the dim...

show abstract

Experimental high-dimensional two-photon entanglement and violations of generalized Bell inequalities

Cited by 634 publications

References 31 publications

Interface between path and orbital angular momentum entanglement for high-dimensional photonic quantum information

Interface between path and orbital angular momentum entanglement for high-dimensional photonic quantum information

Orbital-angular-momentum entanglement in turbulence

Generation and confirmation of a (100 × 100)-dimensional entangled quantum system

Contact Info

Product

Resources

About