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: New research signals big future for quantum radar

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

New filter could advance terahertz data transmission

Feb 27, 2015

University of Utah engineers have discovered a new approach for designing filters capable of separating different frequencies in the terahertz spectrum, the next generation of communications bandwidth that ...

The super-resolution revolution

Feb 27, 2015

Cambridge scientists are part of a resolution revolution. Building powerful instruments that shatter the physical limits of optical microscopy, they are beginning to watch molecular processes as they happen, ...

Precision gas sensor could fit on a chip

Feb 27, 2015

Using their expertise in silicon optics, Cornell engineers have miniaturized a light source in the elusive mid-infrared (mid-IR) spectrum, effectively squeezing the capabilities of a large, tabletop laser onto a 1-millimeter ...

A new X-ray microscope for nanoscale imaging

Feb 27, 2015

Delivering the capability to image nanostructures and chemical reactions down to nanometer resolution requires a new class of x-ray microscope that can perform precision microscopy experiments using ultra-bright ...

New research signals big future for quantum radar

Feb 26, 2015

A prototype quantum radar that has the potential to detect objects which are invisible to conventional systems has been developed by an international research team led by a quantum information scientist at the University ...

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.