CHICAGO, ILLINOIS — An interdisciplinary team of chemists and physicists at Northwestern University (NU) and the University of Chicago (Uchicago) has developed a new method to create tailor-made qubits, short for quantum bits, by chemically synthesizing molecules that encode quantum information into their magnetic, or “spin,” states.
Qubits work by harnessing a phenomenon called superposition. While the classical bits used by conventional computers measure either 1 or 0, a qubit can be both 1 and 0 at the same time.
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, the team 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.
The results, posted on NU’s website on Tuesday, have been published in the journal Science.