In new step toward quantum tech, scientists synthesize ‘bright’ quantum bits

In new step toward quantum tech, scientists synthesize ‘bright’ quantum bits. With their ability to harness the odd powers of quantum mechanics, qubits, like powerful new types of computers or ultra-precise sensors, are the basis for potentially world-changing technologies.

Qubits are often made of the same semiconducting materials as our everyday electronics (short for quantum bits). But the University of Chicago and Northwestern University's interdisciplinary team of physicists and chemists has developed a new method for creating tailor-made qubits: by chemically synthesising molecules into their magnetic, or 'spin,' states that encode quantum information.

This new bottom-up approach could ultimately lead to quantum systems that have extraordinary flexibility and control, helping pave the way for next-generation quantum technology.

“This is a proof-of-concept of a powerful and scalable quantum technology,” said David Awschalom, the Liew Family Professor in Molecular Engineering at University of Chicago’s Pritzker School of Molecular Engineering who led the research along with his colleague Danna Freedman, Professor of Chemistry at Northwestern University. “We can harness the techniques of molecular design to create new atomic-scale systems for quantum information science. Bringing these two communities together will broaden interest and has the potential to enhance quantum sensing and computation.”

The results were published Nov. 12 in the journal Science.

By harnessing a phenomenon called superposition, Qubits operate. While the classical bits used by conventional computers measure either 1 or 0, at the same time, a qubit can be both 1 and 0.

An interdisciplinary team at the University of Chicago and Northwestern University has developed a way to synthesize tailor-made molecular qubits.

The team wanted to find a new bottom-up approach to develop molecules whose spin states can be used as qubits, and can be readily interfaced with the outside world. To do so, they used organometallic chromium molecules to create a spin state that they could control with light and microwaves.

By exciting the molecules with precisely controlled laser pulses and measuring the light emitted, they could “read” the molecules’ spin state after being placed in a superposition—a key requirement for using them in quantum technologies.

By varying just a few different atoms on these molecules through synthetic chemistry, they were also able to modify both their optical and magnetic properties, highlighting the promise for tailor-made molecular qubits.

One potential application for these molecules could be quantum sensors that are designed to target specific molecules. Such sensors could find specific cells within the body, detect when food spoils, or even spot dangerous chemicals.

This bottom-up approach could also help integrate quantum technologies with existing classical technologies.

Daniel Laorenza, a Northwestern University graduate student and co-first author, sees tremendous chemical innovation potential in this space. "This chemically specific environment control around the qubit provides a valuable feature for integrating molecular qubits that are optically addressable into a wide range of environments," he said.

Other authors on the paper include UChicago graduate students Peter Mintun and Berk Diler Kovos.


Article Edited and Republished for CTen by Suraj Maity