New quantum tool developed in groundbreaking experimental achievement

Each day comes up with a new milestone in technology. Technology is advancing every day and easing human efforts. Researchers at the Institute of Quantum Computing(IQC) have developed a device that generates twisted neutrons with well-defined orbital angular momentum. This type of development is for the first time in experimental history. 

Keywords: Quantum Computing, neutrons, silicon grating structures, orbital angular momentum

Dr. Dusan Sarenac is a research associate with IQC and technical lead of Transformative Quantum Technologies at the University of Waterloo. He said, "Neutrons are a powerful probe for the characterization of emerging quantum materials because they have several unique features. They have nanometer-sized wavelengths, electrical neutrality, and a relatively large mass. These features mean neutrons can pass through materials that X-rays and light cannot".

Methods for the experimental production and analysis of orbital angular momentum in photons and electrons are well-studied. But a device design using neutrons has never been demonstrated to date. Because of the distinct characteristics of neutrons, the researchers had to construct new devices and create novel methods with the aim of working with neutrons.

For the development of this device, Dr. Dmitry Pushin, IQC and Department of Physics and Astronomy faculty member at Waterloo with his team constructed microscopic fork-like silicon grating structures. These devices are very minuscule. They are such minuscule that in an area of only 0.5cm by 0.5cm, there are over six million individual fork dislocation phase gratings. The individual neutrons begin winding in a corkscrew pattern as soon as a beam of single neutrons passes through this device. For about traveling 19 years after, an image of the neutrons was captured. The image was captured using a special neutron camera.

The team of researchers observed that every neutron had expanded 10cm wide. It was expanded to a wide donut-like signature. The donut pattern of the propagated neutrons indicated that they have been put in a special helical state. It also indicated the grating devices developed by the team of researchers have generated neutron beams with quantized orbital angular momentum. 

Researcher Pushin said, "Neutrons have been popular in the experimental verification of fundamental physics, using the three easily accessible degrees of freedom: spin, path, and energy. In these experiments, our group has enabled the use of orbital angular momentum in neutron beams, which will essentially provide an additional quantized degree of freedom. In doing so, we are developing a toolbox to characterize and examine complicated materials needed for the next generation of quantum devices such as quantum simulators and quantum computers".

This type of development was once considered to be impossible. But the groundbreaking accomplishment of this research has made a new way for researchers to study the development of next-generation quantum materials. The applications of these quantum materials range from quantum computing to identifying and solving new problems in fundamental physics.