A recent paper in the journal Science announced the discovery of something genuinely and strangely new that could have a huge impact on our ability to chemically engineer advanced materials. A team of quantum scientists from IBM, the University of Manchester, Oxford University, ETH Zurich, EPFL and the University of Regensburg created and characterized a new molecule unlike any other — with a quirk in its shape that can be turned on and off to change how electrons corkscrew through it and alter its chemical behavior. (Note: IBM is an advisory client of my firm, Moor Insights & Strategy.)
This experiment wasn’t the result of trying to incrementally improve an existing molecule. It created a brand new form of matter never before synthesized, observed or predicted. The new molecule’s chemical formula sounds innocent enough: C13CL2. That means it is composed of 13 carbon atoms and two chlorine atoms. That is an unremarkable-sounding formula for such an unusual chemical compound. But what C13CL2 does with its electrons is not only stunning, but unlike anything we have seen before. And it begins with its exotic topology.
A Molecular Strip With A Twist — Plus 3 More
Topology is the branch of mathematics that studies geometric shapes and spaces, and it can have important applications for certain types of molecules. The color bands in the image above represent the physical and mathematical properties of a Möbius strip’s surface, applied at the molecular level. To start an explanation of the topology of this new molecule, imagine tracing an electron as it travels around a plain circle. After one revolution, you’re back where you began. We could call that routine path a topologically trivial system.
Now, consider an ordinary Möbius strip, which connects back to itself only after completing a twist. By tracing a line along the strip’s surface, you must travel around twice to return to your starting point. While molecules with a Möbius topology are rare, scientists have been aware of their existence for quite some time.
The newly created molecule is far more complicated than a plain Möbius strip. The half-Möbius has an electronic structure that spins a helical path through the molecule. Once an electron makes a full revolution around the ring, its electronic phase shifts by 90 degrees; for it to return to its original phase and orientation, it must make four full loops.
Although a half-Möbius body was already known in mathematics, before now the idea of a molecule with half-Möbius topology had not been considered.
Building Matter, One Atom At A Time
The C13CL2 molecule wasn’t an accident of nature, and no one stumbled across it in the corner of a lab. The researchers used IBM superconducting-qubit quantum processors, accessed via the IBM Quantum Platform, to characterize the molecule. Specifically, runs of up to 100 qubits were executed on IBM Heron processor hardware available through the IBM Pittsburgh system. The procedure for creating it was carried out with extremely precise voltage pulses in ultra-high vacuum at near-absolute-zero temperatures.
An interesting historical connection: One of the technologies that made this discovery possible was the scanning tunneling microscope invented at IBM Research Zurich way back in 1981. Its inventors, Gerd Binnig and the late Heinrich Rohrer, won the 1986 Nobel Prize in Physics.
The potential power of the C13CL2 molecule lies in its ability to switch between a right-handed half-Möbius, a left-handed half-Möbius or a topologically trivial configuration. This allows its topology to be engineered, controlled and manipulated depending on the desired results.
Switchability is an important characteristic. A material capable of toggling between topological states on demand could serve as a potential building block for new inventions such as quantum sensing devices, chiral sensors, spin filters and others.
A Problem That Taxes The Best Classical Computers
Creating the molecule was difficult, but understanding why it behaved the way it did was equally challenging. The calculation was complex, to say the least. With all the electrons in C13CL2 entangled in a state where they are all quantumly linked together, it is beyond the computational capability of any classical supercomputer.
As simulations like these scale, quantum computing will soon be the only technology capable of tracking all of the molecule’s configurations simultaneously. In this case, the team used a specialized quantum algorithm called SqDRIFT to simulate the behavior of complex molecules. The algorithm can determine the molecule’s lowest-energy state, which is needed to understand things such as how chemicals react, how new drugs work and how to design more efficient materials. SqDRIFT allowed the team to explore an active computational space of 2^100, which is inaccessible to any classical computer. To put that number in context, if every person on Earth operated a billion computers, each testing a billion keys per second, it would take trillions of times the age of the universe to exhaust that number of possibilities. (This analogy comes from Bruce Schneier in his book Applied Cryptography).
Quantum simulation helped reveal that the cause for the unusual topology was a helical pseudo-Jahn-Teller effect. In plain terms, this is a chemical effect that explains why certain molecules twist or distort rather than remaining symmetrical. Quantum computation also confirmed the prediction of twisted molecular orbitals for electron attachment, a hallmark of the half-Möbius topology.
What’s Next For Electronics, Drug Discovery And More
Historically, our progress in chemistry and solid-state physics has been steady — and impressive. For example, in the 20th century, we learned how to change a molecule’s properties by swapping its parts (substituent effects). The 21st century has given us knowledge of how to store digital information by flipping the magnetic spin of electrons (spintronics).
Now, with the creation of C13CL2 half-Möbius, we appear to be entering a new era of engineering in which topology can serve as an additional switchable degree of freedom, potentially opening up a powerful new route for controlling the molecular properties of materials. In other words, this new topology promises to give us powerful, switchable control for determining how a material behaves.
This breakthrough has the potential to impact several important domains. Molecules with a topological state that can be flipped on demand could be the basis of entirely new classes of switches, sensors or information storage media. Even more tantalizing is the potential impact on drug discovery. Exploring molecular properties with quantum computing has long been touted for that purpose, but the quantum computing simulation pipeline tested on C13CL2 could represent a future workflow in which new drug candidates can be modeled at the electronic level with a fidelity far beyond that of classical computers. If that is possible, it could eliminate years of trial-and-error currently required for pharmaceutical development.
In short, we may look back on this discovery as a meaningful inflection point in the history of quantum computing — one that might eventually reshape whole industries.
Moor Insights & Strategy provides or has provided paid services to technology companies, like all tech industry research and analyst firms. These services include research, analysis, advising, consulting, benchmarking, acquisition matchmaking and video and speaking sponsorships. Of the companies mentioned in this article, Moor Insights & Strategy currently has (or has had) a paid business relationship with IBM.
