Highly stable quantum light source for applications in quantum information developped

Nov 04, 2013

Physicists at the University of Basel have been successful in generating photons - the quantum particles of light – with only one color. This is useful for quantum information. The scientists have actively stabilized the wavelength of the photons emitted by a semiconductor thereby neutralizing the charge noise in the semiconductor. The results were developed in close collaboration with the Universities of Bochum, Paderborn and Lyon and have been published in the magazine Physical Review X.

Light consists of , so-called . With a single photon it is possible to transfer . The information can be encoded in the polarization or in the phase of the photons' wave packets and can be used in and computation. In such applications, a single-photon source, a device that emits photons one by one, is a prerequisite. One of the most promising platforms for single-photon sources is based on . One major unsolved problem is, however, that the "color" (or wavelength) of the photons emitted by a quantum dot is not locked to a precise value; rather, it wanders around randomly.

The fluctuations in the wavelength of the photons originate from imperfections in the vicinity of the quantum dot. These imperfections can trap electric charge in the semiconductor resulting in noise. To remove this "charge noise", Prof. Warburton of the Department of Physics at the University of Basel and his team have developed a quantum-classical hybrid system that connects a single quantum dot to a constant-wavelength laser. This stabilizing mechanism monitors continuously the fluctuations via the highly sensitive optical absorption of the quantum dot. By applying the exact opposite effect, the electrical field experienced by the quantum dot can be actively regulated.

Stream of single-color photons

With this system, the scientists succeeded in generating a nearly perfect stream of single-color photons. A notable point is that a quantum system could be made technically useful by using a classical feedback scheme, a general feature which has not been demonstrated up until now.

This new scheme - through its highly effective removal of the charge noise - potentially enables a stable single-photon source and may lead, for example, to improvement in -based spin quibts. The study was supported by the National Center of Competence in Research "QSIT – Quantum Science and Technology", for which the University of Basel acts as Co-Leading-House.

Explore further: Researchers develop the first-ever quantum device that detects and corrects its own errors

More information: Jonathan H. Prechtel, Andreas V. Kuhlmann, Julien Houel, Lukas Greuter, Arne Ludwig, Dirk Reuter, Andreas D. Wieck, and Richard J. Warburton, Frequency-Stabilized Source of Single Photons from a Solid-State Qubit, Phys. Rev. X 3, 041006 (2013) | DOI: 10.1103/PhysRevX.3.041006

Related Stories

Hi-fi single photons

Oct 04, 2012

Many quantum technologies—such as cryptography, quantum computing and quantum networks—hinge on the use of single photons. While she was at the Kastler Brossel Laboratory (affiliated with the Pierre and Marie Curie University, ...

Recommended for you

The dark side of cosmology

2 hours ago

It's a beautiful theory: the standard model of cosmology describes the universe using just six parameters. But it is also strange. The model predicts that dark matter and dark energy – two mysterious entities ...

Studying effects of target 'tents' on NIF

3 hours ago

A systematic study of the effects on National Ignition Facility (NIF) implosions of the ultra-thin mounting membranes that support target capsules inside NIF hohlraums was reported by LLNL researchers in ...

Mathematicians model fluids at the mesoscale

3 hours ago

When it comes to boiling water—or the phenomenon of applying heat to a liquid until it transitions to a gas—is there anything left for today's scientists to study? The surprising answer is, yes, quite ...

Breakthrough in nonlinear optics research

Mar 05, 2015

A method to selectively enhance or inhibit optical nonlinearities in a chip-scale device has been developed by scientists, led by the University of Sydney. The researchers from the Centre for Ultrahigh bandwidth ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

El_Nose
not rated yet Nov 04, 2013
developped ???

that got past everybody

Highly stable quantum light source for applications in quantum information developped

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.