Chinese scientists make a new quantum chip from a common semiconductor
Chinese researchers have taken a step towards building a quantum chip, using a common semiconductor to create a quantum light source for the first time in the world.
Quantum chips have the potential to solve complex problems exponentially faster than conventional electron-based computing, but scientists have struggled to build the components needed for an integrated circuit.
A Chinese team has now claimed to have created one such component – a quantum light source – using the semiconductor gallium nitride (GaN), a material used for decades in light-emitting diodes. blue.
According to the team from the University of Electronic Science and Technology of China (UESTC), Tsinghua University and the Shanghai Institute of Microsystems and Information Technology, the device has “considerable potential” for building small quantum chips and robust.
The light source produced pairs of quantum-connected, entangled light particles that can be used to carry information.
Compared to existing quantum light sources based on materials such as silicon nitride and indium phosphide, the new device has a much wider wavelength range and could be used to build other major components of a quantum circuit, they the researchers reported in the journal Physical Review Letters last month.
“We demonstrate that gallium nitride is a good quantum material platform for photonic quantum information, where quantum light generation is crucial,” lead author Zhou Qiang of UESTC told Physics Magazine.
“The gallium nitride platform offers promising prospects for the advancement of quantum photonic chips in the near future.”
Quantum optics expert Thomas Walther, of the Technical University of Darmstadt in Germany, told Physics Magazine that the work is “an important step forward” because it could reduce the production costs of such systems and make them much more compact and robust of the current ones.
In their experiment, Zhou and his colleagues first grew a thin film of GaN on a layer of sapphire. Then they etched a ring into the film 120 micrometers in diameter, allowing light particles from the laser beams to travel around the ring.
When the researchers fed infrared laser light into the GaN film, some light particles became trapped and became “resonant” in pairs.
Thanks to an effect known as spontaneous four-wave mixing, some resonant pairs gave rise to a new pair of light particles that became entangled with each other.
The degree of entanglement produced by the GaN ring was "comparable" to the level measured for other quantum light sources, Zhou explained to the journal Physics. The range of output wavelengths also extended from the 25.6 nanometers of the materials earlier than the 100 nanometers of the new device.
“By providing more wavelength resources, we will be able to meet the needs of more users hoping to access a quantum network across different wavelengths,” Zhou told Science and Technology Daily on Thursday.
In addition to the quantum light source, GaN is also a promising material for making other components of a quantum circuit, including the pump laser and light particle detectors, according to the team.
“The GaN platform is very promising for realizing all-on-chip quantum photonic integrated circuits compared to existing platforms,” they said.
We hope that this new form of quantum light and circuit will also be able to overcome the big problem that, so far, is slowing down, if not canceling, the progress of quantum computation, namely "noise" , i.e. the extreme sensitivity to any environmental variation , such as, for example, disturbances caused by photons, or heat, which can disturb, or even cancel out, the computational capacity of quanta.
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This is a machine translation of a post published on Scenari Economici at the URL https://scenarieconomici.it/scienziati-cinesi-realizzano-un-nuovo-chip-quantistico-da-un-semiconduttore-comune/ on Thu, 25 Apr 2024 06:00:52 +0000.