American engineers have developed a chip that converts visible light into infrared light and can switch back while keeping the original photon's quantum state. This capability will allow quantum devices to transmit information to each other over the existing fiber infrastructure. The researchers say this is an important step towards implementing a quantum networked device and computer that can exchange information. For over a decade, researchers have been developing techniques to build a network of quantum devices that can transmit quantum information over long distances. Examples of these quantum devices include rubidium atoms and nitrogen vacancy center atoms in the supercooled gas. In these systems, confidence is preserved in the physical state of individual particles, known as qubits and qubits. Like a transistor in a classic circuit, these qubits can be calculated. In addition, quantum information can be exchanged between fixed bits using these photons as "flying bit cells." An important challenge is how to connect the output of one quantum device to another, said Tang Hong, an electrical engineer at Yale University and involved in the research. When two quantum devices are based on two different physical systems, their output photons are not on the same frequency. "Unfortunately, most quantum devices operate at different frequencies and do not really communicate with each other," he said. Light of different frequencies Even if the device is based on the same physical system, it can be troublesome when quantum information must travel over long distances. One of the problems is that the purpose of a fiber optic network design is to emit infrared light while some quantum bit operations operate in the visible frequency range. The new chip enables two devices to operate at different frequencies and exchange information over long distances using existing infra-red fiber infrastructure. For example, if a visible-light photon is emitted by a rubidium-based device, the photonic chip will convert the light to the infrared and then transmit it over the fiber optic network to form the Internet. The chip connected to the second quantum device can then receive this infrared light and convert it into system-recognizable visible light. Don's team was the first to achieve this exact frequency conversion on the chip. Unlike previous methods, these chips can be mass-produced inexpensively. Nonlinear ring The conversion of the frequency is carried out by means of a small semiconductor ring on a chip made of aluminum nitride. Through the non-linear effect of light, this ring can produce different light frequencies. Tang's team guided infrared and visible laser light into the ring through the waveguide. They show that using an approach called "beat frequency", an infrared signal can be created at different frequencies. When they emit two infrared beams, they show that visible light can be generated by a process called "double frequency." "This is an important first step," said Arka Majumdar of the University of Washington, who did not participate in the study. He is also working on a future Quantum Network Infrastructure-related device. "This chip is like a wire in a classic circuit," he explained. Next, Tang said that in order to improve the chip's frequency conversion efficiency. In the paper, they reported a 14% efficiency. But this is due to bad links, Don said. In future experiments, they will aim to improve the conversion efficiency up to 100%, and they have demonstrated that semiconductors can do this. Single photon Majumdar noted that Don and his colleagues have demonstrated that their chips can effectively convert a single visible light. But he still has high hopes: "In 10 years, I think we will be able to truly communicate between the two quantum systems," he said. Related papers on this chip structure have been published in the "Physical Review Letters" magazine. Used Pipe Elevators,Elevators For Drilling Pipe ,Double Latch Elevator For Tubing,Ta Tubing Elevator JIANGSU PETROLEUM MACHINERY CO.,LTD , https://www.jspmgroup.com