Quantum teleportation on a photonic chip

Quantum teleportation is a fundamental concept in quantum physics which now finds important applications at the heart of quantum technology including quantum relays, quantum repeaters and linear optics quantum computing (LOQC). Photonic implementations have largely focussed on achieving long distance teleportation due to its suitability for decoherence-free communication. Teleportation also plays a vital role in the scalability of photonic quantum computing, for which large linear optical networks will likely require an integrated architecture. Here we report the first demonstration of quantum teleportation in which all key parts - entanglement preparation, Bell-state analysis and quantum state tomography - are performed on a reconfigurable integrated photonic chip. We also show that a novel element-wise characterisation method is critical to mitigate component errors, a key technique which will become increasingly important as integrated circuits reach higher complexities necessary for quantum enhanced operation.Comment: Originally submitted version - refer to online journal for accepted manuscript; Nature Photonics (2014

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

Interference between independent single photons is perhaps the most fundamental interaction in quantum optics. It has become increasingly important as a tool for optical quantum information science, as one of the rudimentary quantum operations, together with photon detection, for generating entanglement between non-interacting particles. Despite this, demonstrations of large-scale photonic networks involving more than two independent sources of quantum light have been limited due to the difficulty in constructing large arrays of high-quality, single-photon sources. Here, we solve the key challenge, reporting on a novel array of five near-identical, low-loss, high-purity, heralded single-photon sources using spontaneous four-wave mixing on a silica chip. We verify source quality through a series of heralded Hong–Ou–Mandel (HOM) experiments, and further report the experimental three-photon extension of the HOM interference effect, which maps out for the first time, to our knowledge, the interference landscape between three independent single-photon sources

High quantum efficiency photon-number-resolving detector for photonic on-chip information processing

We demonstrate a high-efficiency, photon-number resolving transition edge sensor, integrated on an optical silica waveguide structure. The detector consists of three individual absorber/sensor devices providing a total system detection efficiency of up to 93% for single photons at a wavelength of 1551.9 nm. This new design enables high fidelity detection of quantum information processes in on-chip platforms

High-efficiency Bragg grating enhanced on-chip photon-number-resolving detectors

The recent trend towards integration of quantum optics experiments has produced a demand for on-chip single photon detectors with high quantum efficiencies. In previous work we demonstrated integrated photon number resolving detectors for use at telecommunications wavelengths [1], here we outline developments of this design which have enabled improvements in the quantum efficiency, permitting an on-chip detection efficiency of 92% to be obtained in the device of Fig. 1. ..

Single-component plasma of photoelectrons ATRAP Collaboration

Abstract Ten-nanosecond pulses of photoelectrons liberated by intense UV laser pulses from a thin gold layer are captured into a single-component plasma that is ideally suited to cool antiprotons (p) for antihydrogen (H) production. Up to a billion electrons are accumulated using a series of laser pulses, more than are needed for efficientp cooling in the large traps now being used for loadingp forH production. The method is demonstrated within an enclosed vacuum space that is entirely at 4 K, and is thus compatible with the exceptional cryogenic vacuum that is desirable for the long-term storage of antihydrogen. The pitfalls of other electron accumulation methods are entirely avoided, including the particle heating and declining efficiency of field emission point loading, and the heat load and contamination of thermionic emission methods. © 2007 Elsevier B.V. All rights reserved. The quantum explanation of the surprising photoelectrons that light liberates from a metal surface was one of the early successes of a quantum view of the world Here we report the first use of short pulses of photoelectrons to quickly and robustly accumulate the large number of electrons needed to collisionally cool antiprotons (p)-a crucial step for slowH production [9-11]. CERN's unique Antiproton Decelerator facility (AD) delivers 5-MeVp. These are slowed to the keV energies at which they can be trapped-either i