Molecular qubits can communicate at telecom frequencies

A team of scientists from the University of Chicago, the University of California Berkeley, the National Laboratory of Argonne, and Lawrence Berkeley National Laboratory has developed molecular qubits that fill the gap between light and magnetism – and operate at the same frequencies as telecommunications technology. Advance, published today in ScienceEstablish a new promising constitutive block for evolutionary quantum technologies which can be integrated transparently into existing fiber networks.

Because new molecular qubits can interact in telecommunications frequencies, work points to future quantum networks – sometimes called “quantum internet”. These networks could allow ultra-secure communication channels, connect quantum computers over long distances and distribute quantum sensors with unprecedented precision.

Molecular qubits could also serve as very sensitive quantum sensors; Their small size and chemical flexibility mean that they could be integrated into unusual environments – such as biological systems – to measure magnetic fields, temperature or pressure on the nanometric scale. And because they are compatible with silicon photonics, these molecules could be integrated directly into fleas, opening the way to compact quantum devices that could be used for IT, communication or detection.

The new molecular qubit contains the Erbium, a rare-terrace. Rare earths are used in conventional technologies as well as in emerging quantum technologies because they absorb and emit light very “properly” compared to other elements, but they also interact strongly with magnetic fields.

“These molecules can act as a bridge on a nanometric scale between the world of magnetism and the world of optics,” said Leah Weiss, postdoctoral scholar at the school of molecular engineering at the University of Chicago Pritzker (Uchicago PME) and co-first author on the newspaper. “The information can be coded in the magnetic state of a molecule, then accessible with light to wavelengths compatible with well-developed technologies underlying with optical fiber networks and photonic silicon circuits.”

At the quantum level, the relationship between light and magnetism is subtle and complex. Light is often the way quantum information is transmitted and read; Magnetism is deeply connected to “spin”, a single quantum property that underlies a variety of quantum technologies such as sensors and certain types of quantum computers.

This work is based on a base of two areas, quantum optics – with applications in lasers and quantum networks – and synthetic chemistry – which is responsible for contrast agents used in magnetic resonance imaging machines (MRI) – to establish a molecular construction element that can make the gap between them.

“The chemistry of the rare earth has provided a fortuitous combination of properties which allowed us to bring these capacities to a molecular system,” said Grant Smith, a student graduated from SMEs and another first author on the newspaper.

“There were a lot of things that pointed out towards this as an exciting platform to advance the use of optical degrees of freedom in molecular spin qubits. One of the central objectives of this work, and work in the laboratory more broadly, is that we really want to extend the range of quantum systems and materials that we can control and interact.” In doing so, he says: “You can start thinking about new unconventional ways to use them and integrate them into technologies.”

Using optical spectroscopy and microwave techniques, the team has shown that Erbium molecular qubits used frequencies compatible with silicon photonics, which are used in telecommunications, high performance IT and advanced sensors. Researchers say that this compatibility with mature technologies could accelerate the development of hybrid molecular platforms for quantum networks.

“By demonstrating the versatility of these molecular quit of the Erbium, we make another step towards evolving quantum networks which can connect directly to today’s optical infrastructure,” said David Awschalom, Liew family teacher as a molecular and physical engineering at the University of Chicago and the study of the study.

“We have also shown that these atomic modified qubits have the necessary capacities for multi-qued architectures, which opens the door to a wide range of applications, including quantum detection and organic-inorganic hybrid systems.”

Weiss and Smith highlighted the importance of their collaboration with the chemists of the Berkeley, in particular their co-author Ryan Murphy in the research group of Jeffrey Long, the appellant “absolutely critical” at work and “a privilege”.

“Synthetic molecular chemistry offers the opportunity to optimize the electronic and optical properties of rare earth ions in a manner that can be difficult to access in conventional solid state substrates,” said Murphy. “This study only scrapes the surface of what we think we can accomplish.”

“Our work shows that synthetic chemistry can be used to design and control quantum materials at the molecular level,” said Long, professor of chemistry at UC Berkeley and co-printing investigator. “This indicates a powerful path to create tailor -made quantum systems with applications in networking, detection and calculation.”