Recently, the Team of the University of Hong Kong made a breakthrough in quantum device manufacturing, developing a nanoscale precision printing method to print the nitrogen-vacancy color center in diamond nanoparticles at the quantum level.
The new technology prints nanodiamonds containing NV color centers with nanoscale precision, image from the University of Hong Kong
For physicists, diamonds are more attractive as gemstones, where imperfections are more attractive. The nitrogen-vacancy center (NV center) is one of the most common point defects in the crystal structure of diamond (the rough of diamond) and is currently the most representative quantum system. NV color centers are solid-state devices at the atomic level, and as an important quantum material, it has optically adjustable spin freedom, with core functions such as qubits and quantum detectors in solid-state quantum processors.
Today's quantum systems, such as superconducting quantum interferometers, can only operate at very low temperatures (150°C to absolute zero 273°C). Since the NV color center also has a strong quantum state at room temperature, this is especially important for implementing room temperature quantum devices.
To implement related applications, a core requirement for quantum technology is to precisely place a single NV color center on the integrated circuit. This technological breakthrough will drive the development of important emerging fields such as quantum computers, quantum communications and quantum biological perception.
However, the current technical obstacles mainly include problems such as rough positioning accuracy, low throughput and complex process. Several existing schemes position nanodiamond particles with NV color centers on a variety of substrates and circuits, including complex "pick and place" nano-manipulation methods, which are not ideal.
This time, the research team led by Ji Tae Kim, Ph.D. of Mechanical Engineering, Faculty of Engineering, The University of Hong Kong, and Zhiqin Chu, Ph.D. of the Department of Electrical and Electronic Engineering, developed a nanoscale precision printing method to print the NV color centers in diamond nanoparticles at the quantum level. The results were published in Advanced Science, which was selected as a current featured story at the bottom of the journal and has applied for a U.S. patent for an invention.
Current selected research at the bottom of the journal Advanced Science
In the past, diamonds were the hardest materials, so they were difficult to process. The new approach in this study is sufficient to address this challenge, and the team adopted a sublitre droplet containing nanodiamond (
"There is a great need for a versatile and flexible diamond particle positioning method that combines excellent scalability, controllable costs, and compatibility with a wide range of nanophoton circuits." Chu Zhiqin said, "The new technology we have developed can reflect the positioning accuracy of sub-wavelengths, the quantitative control level of single defect stages and the ability of free patterning, and meet the relevant technical requirements." This novel approach will open up a practical and cost-effective way out for the manufacture of quantum devices such as quantum information processors, quantum calculators and biosensors. ”
The NV color centers printed at the quantum level, a is a confocal fluorescence image, b is the second-order correlation function g(2)(τ) of the corresponding fluorescent point, c Histogram of the number distribution of NV color centers printed for each point, picture from the University of Hong Kong