Shifting quantum photonics

Quantum computers use basic elements of quantum mechanics to potentially increase the speed of the process of solving complex calculations. Suppose you have to perform the task of searching for a specific number in a phonebook. A classic computer will search every line of the phonebook until it finds a match. A quantum computer could search the entire directory at the same time by considering each line at the same time and delivering a much faster result.

The difference in speed is due to the computer's basic information processing unit. In a classic computer, the basic unit is called a bit, an electrical or optical pulse representing either 0 or 1[ads1]. A quantum computer's basic unit is a qubit, which can represent a variety of combinations of values ​​from 0 and 1 at a time. It is this property that can allow quantum machines to speed up calculations. The disadvantage of qubits is that they exist in a fragile quantum state that is vulnerable to environmental noise, such as temperature changes. As a result, generating and managing receipts in a controlled environment presents significant challenges for researchers.

UC Santa Barbara engineer Galan Moody, assistant professor of electrical and computer engineering, has proposed a solution to overcome the poor efficiency and performance of existing quantum computing prototypes that use light to encode and process information. Optical systems are attractive because they naturally link quantum computing and networks in the same physical framework. However, existing technology still requires off-chip optical operations, which dramatically reduce efficiency, performance and scalability. In his project, "Heterogeneous III-V / Silicon Photonics for All-on-Chip: Linear Optical Quantum Computing," Moody aims to create an optical quantum computing platform where all important components are integrated into a single semiconductor chip. [19659005] "Integrated electronic circuits enabled revolutionary advances in classical computing. Our goal is to create integrated photonic circuits that have the same impact on quantum computing," said Moody, who joined UCSB's College of Engineering in the fall after spending six years at the National Institute of Standards and Technology as a postdoctoral fellow and researcher. "This can lead to a dramatic improvement in efficiency and processing speed and enable entirely new methods of processing and transmitting information using light."

Moody's research project has now received a significant boost from the United States Air Force. He is one of 40 early-career researchers selected for a Young Investigator Award in 2019 from the Swedish Defense Air Force's Office of Scientific Research. Winners receive $ 450,000 over three years to support their work. The program is intended to promote research by young scientists who support the Air Defense's mission to control and maximize the utilization of air, space and cyberspace, as well as related challenges in science and engineering.

"It is an honor to be among this group of talented award recipients, and I am grateful that I was chosen," Moody said. "This award will allow my research team to have a more meaningful impact on the exciting and rapidly evolving quantum information landscape."

To develop an all-electric, all-on-chip quantum photonic platform, Moody proposes to integrate three technologies developed for different platforms and applications. The components are electrically powered single photon sources, silicon based photonics for optical operations, and superconducting nanowire single photon detectors.

"We use physical modeling to guide the design and fabrication of the device," he says. so. "Quantum optical spectroscopy will give us insight into material properties and noise sources, and optical interferometers on the chip will allow measurements to improve the material's purity, monitor the light source and perform calculations. Finally, we want to understand and exploit the benefits that quantum mechanics can provide for data processing and network. "

According to Moody, the new technology can also have transformative effects in areas such as turnkey quantum light sources for secure communication, and to reduce the size, weight and power consumption of classic photonic devices such as lasers and LEDs.