Optical photons are supreme carriers of quantum info. However to work collectively in a quantum pc or community, they should have the identical shade — or frequency — and bandwidth. Altering a photon’s frequency requires altering its power, which is especially difficult on built-in photonic chips.
Not too long ago, researchers from the Harvard John A. Paulson College of Engineering and Utilized Sciences (SEAS) developed an built-in electro-optic modulator that may effectively change the frequency and bandwidth of single photons. The machine may very well be used for extra superior quantum computing and quantum networks.
The analysis is revealed in Gentle: Science & Purposes.
Changing a photon from one shade to a different is often achieved by sending the photon right into a crystal with a robust laser shining by means of it, a course of that tends to be inefficient and noisy. Section modulation, through which photon wave’s oscillation is accelerated or slowed down to alter the photon’s frequency, affords a extra environment friendly technique, however the machine required for such a course of, an electro-optic section modulator, has confirmed tough to combine on a chip.
One materials could also be uniquely suited to such an software — thin-film lithium niobate.
“In our work, we adopted a brand new modulator design on thin-film lithium niobate that considerably improved the machine efficiency,” mentioned Marko Lončar, the Tiantsai Lin Professor of Electrical Engineering at SEAS and senior writer of the research. “With this built-in modulator, we achieved record-high terahertz frequency shifts of single photons.”
The staff additionally used the identical modulator as a “time lens” — a magnifying glass that bends mild in time as a substitute of house — to alter the spectral form of a photon from fats to skinny.
“Our machine is rather more compact and energy-efficient than conventional bulk gadgets,” mentioned Di Zhu, the primary writer of the paper. “It may be built-in with a variety of classical and quantum gadgets on the identical chip to appreciate extra subtle quantum mild management.”
Di is a former postdoctoral fellow at SEAS and is presently a analysis scientist on the Company for Science, Analysis and Expertise (A*STAR) in Singapore.
Subsequent, the staff goals to make use of the machine to regulate the frequency and bandwidth of quantum emitters for functions in quantum networks.
The analysis was a collaboration between Harvard, MIT, HyperLight, and A*STAR.
The paper was co-authored by Changchen Chen, Mengjie Yu, Linbo Shao, Yaowen Hu, C. J. Xin, Matthew Yeh, Soumya Ghosh, Lingyan He, Christian Reimer, Neil Sinclair, Franco N. C. Wong, and Mian Zhang.
This analysis was funded by the Harvard Quantum Initiative (HQI), Military Analysis Workplace/Protection Superior Tasks Company (DARPA) (W911NF2010248), Air Drive Workplace of Scientific Analysis (FA9550-20-1-01015), DARPA Lasers for Common Microscale Optical Programs (HR0011-20-C-0137), Division of Power (DE-SC0020376), Nationwide Science Basis (EEC-1941583), Air Drive Analysis Laboratory (FA9550-21-1-0056), HQI post-doctoral fellowship, A*STAR SERC Central Analysis Fund (CRF), and Pure Sciences and Engineering Analysis Council of Canada (NSERC).