If you need to emboss leather-based, you press a stamp into the fabric, abandoning a sample in aid. Several years in the past, chemist Thomas Kempa envisioned {that a} related precept could possibly be used to sample new bodily states inside two-dimensional crystals. Today, his “lattice embossing” approach can be utilized to elicit distinctive properties with potential purposes in quantum computing and next-generation sensors and devices.
Image caption: Thomas Kempa
Image credit score: Will Kirk / Johns Hopkins University
Kempa, an affiliate professor in Johns Hopkins University’s Department of Chemistry, simply acquired a five-year, $1.3 million award from the Gordon and Betty Moore Foundation to broaden his new idea. The basis describes its Experimental Physics Investigators Initiative as “advancing the frontier of fundamental research in experimental physics by supporting brilliant mid-career scientists.”
Kempa referred to as the assist “transformational.” While a breakthrough not too long ago validated the lattice embossing idea, the Moore Foundation grant will permit him to put the groundwork for a brand new area that explores and controls basic excitations inside two-dimensional crystals. Precise management over these excitations (excitons, phonons, and magnons) and their long-range order lies on the coronary heart of unlocking expertise breakthroughs.
“The big vision lies in figuring out how to use our lattice embossing platform to create a next-generation quantum computer that runs on excitons,” Kempa mentioned.
Kempa is considered one of 22 researchers named to the Moore Foundation’s 2025 cohort. Experimental Physics Investigators obtain $1.3 million over 5 years to pursue modern analysis targets and take a look at new concepts unlikely to draw monetary assist from standard funding sources, in keeping with the muse’s web site. The program is designed to supply scientists the pliability to pivot as their analysis dictates.
Kempa says he set out on his “passion project” properly conscious of the guarantees and limitations of current methods for extracting new phenomena from 2D supplies. “What if I just design a periodic potential, with the right symmetry and size, and place it in contact with a 2D crystal? What will happen then?” he requested himself.
For a long time, scientists have been utilizing a software referred to as scanning tunneling microscopy to control matter on the atomic scale. This methodology includes bringing a metallic tip near a substance’s floor and making use of a voltage potential. The voltage can then be used to maneuver electrons from the tip into the substance, or to shift particular person atoms to different close by positions. What if, Kempa puzzled, you could possibly organize billions of the following tips into any sample you need, after which use them to impose new properties onto the fabric beneath?
Since creating such an array of ideas utilizing standard fabrication routes is something however reasonable, Kempa turned to what he calls the chemist’s toolbox and realized {that a} molecular lattice—particularly, a metal-organic framework, or MOF—could possibly be used to perform a lot of what he envisioned.
Hybrid supplies with programmable properties, MOFs characteristic massive pores usually used to retailer gases. Kempa got here up with the thought of slicing by way of a MOF to acquire a single layer with a unit cell that repeats in two dimensions. This lattice, he defined, has molecular teams which might be usually positioned with atomic precision above and under the aircraft of the MOF crystal. By tuning the dimensions, spacing, cost state, and sample of those teams, he was ready to make use of them similar to the little ideas in a scanning tunneling microscope, localizing and tuning the quantum options of the excitons within the floor he utilized them to.
At first, the thought appeared nearly as unrealistic as producing billions of metallic ideas. He had to determine tips on how to develop MOFs as pristine single layers, tips on how to program the MOFs to tackle the shapes and symmetries he needed, and tips on how to construct gadgets that include the MOFs whereas harboring excellent interfaces with the fabric under. The first breakthrough got here when he utilized—or embossed—the MOF to a two-dimensional tungsten diselenide semiconductor, reworking the semiconductor’s beforehand undefined emissions into slender, well-defined quantum emissions.
“We had the crazy idea that merging molecular lattices that have the right design with other 2D materials can basically open up a plethora of new possibilities in controlling quasi-particle states,” Kempa mentioned. In concept, as researchers study to restrict, direct, and manipulate the excitons’ quantum options, they’re going to be capable to make complete {hardware} platforms to retailer cost, do computation, and transmit info over lengthy distances.
The Kempa analysis group’s experience spans the areas of bodily, inorganic, and supplies chemistry. Lab members develop new strategies to arrange and examine low-dimensional inorganic crystals from nanoparticles to molecular wires to sheets just a few atoms thick, whose distinctive properties render them intriguing platforms for optoelectronic gadgets, vitality conversion techniques, and quantum computing architectures.
Kempa’s earlier honors embrace a DARPA Young Faculty Award, an NSF CAREER Award, a Toshiba Distinguished Young Investigator Award, a Dreyfus Foundation Fellowship in Environmental Chemistry, and two Johns Hopkins Discovery Awards. He was additionally named a Kavli Fellow by the National Academy of Sciences and a Mercator Fellow by the German Research Foundation. Kempa is a co-founder and co-director of the Hub for Imaging and Quantum Technologies, a Bloomberg Distinguished Professor cluster at Hopkins.