quantum dot tagged posts

Quantum Emitters: Beyond Crystal Clear to Single-Photon Pure

Nanoscale luminescence quenching occurs when a focused ion beam is irradiated. By selectively quenching the uncorrelated light, one can increase the single-photon purity from the quantum emitter without optical degradation and structural destruction

A research team has developed a technique that can isolate the desired quality emitter by reducing the noise surrounding the target with what they have dubbed a ‘nanoscale focus pinspot.’

Photons – fundamental particles of light – are carrying these words to your eyes via the light from your computer screen or phone. Photons play a key role in the next-generation quantum information technology, such as quantum computing and communications...

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A Breakthrough that Enables Practical Semiconductor Spintronics

Illustration of the nanostructure.
In the opto-spintronic nanostructure, an electron spin polarisation degree greater than 90% is achieved at room temperature in a quantum dot, via remote defect-enabled spin filtering through an adjacent layer of gallium nitrogen arsenide (GaNAs). When such a spin polarised electron recombines, it emits chiral light. The spin state of the electron determines whether the electromagnetic field of the light will rotate clockwise or anticlockwise around the direction of travel. Yuqing Huang

It may be possible in the future to use information technology where electron spin is used to store, process and transfer information in quantum computers. It has long been the goal of scientists to be able to use spin-based quantum information technology at room temperature...

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Ultra-Bright light: A New Source of Quantum Light

3 sources of single photons: represented by a red dot at the center of the cavity, the semiconductor quantum dots (of nanometric size) is inserted in the center of the cavity, which consists of a 3 µm pillar connected to a circular frame by guides that are 1.3 µm wide. By applying electrical voltage to the cavity, the wavelength of the emitted photons can be tuned and the charge noise totally eliminated. Credit: © Niccolo Somaschi – Laboratoire de photonique et de nanostructures (CNRS)

3 sources of single photons: represented by a red dot at the center of the cavity, the semiconductor quantum dots (of nanometric size) is inserted in the center of the cavity, which consists of a 3 µm pillar connected to a circular frame by guides that are 1.3 µm wide. By applying electrical voltage to the cavity, the wavelength of the emitted photons can be tuned and the charge noise totally eliminated. Credit: © Niccolo Somaschi – Laboratoire de photonique et de nanostructures (CNRS)

A new ultra-bright source of single photons – 15X brighter than commonly used sources and emitting photons that are 99.5% indistinguishable from one another – has been developed by researchers from the CNRS, Université Paris Diderot, and Université Paris-Sud...

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