Alex Burgers receives AFOSR support for research on atom-photon interactions

Quantum technologies are poised to revolutionize our data security, sensing capabilities, and computing performance, surpassing the limits of classical technologies. To develop these technologies, researchers must understand, control, and even link together the quantum states of individual atoms. An atom reveals its internal state by emitting light and, conversely, light can alter the internal state of an atom—therefore, understanding atom-photon interactions is fundamental to the progression of quantum technology. To further this research, Prof. Alex Burgers plans to develop a new method for creating strong interactions between atoms and photons, supported by a new grant from the Air Force Office of Scientific Research (AFOSR). 

Research on atom-photon interactions has traditionally been done by putting a single atom into a cavity formed by two glass mirrors to enhance the interactions between the atom and light. Researchers can gain information about the atom by observing the light that it emits into the cavity. However, using glass—or other macroscopic, dielectric—objects introduces defects into the system.

Burgers’ work seeks to replace these classical dielectric mirrors with arrays of atoms that behave like mirrors.  A closely spaced 2-dimensional array of atoms will experience collective effects leading to destructive interference when excited, similar to a closely spaced array of classical dipole antennas. This effect causes external light to reflect off the 2D array, forming an atomic mirror. In practice, this phenomenon has been very difficult to demonstrate or explore.

Burgers’ lab will trap individual ytterbium atoms in tightly focused laser beams called optical tweezers. Using multiple optical tweezers, he can arrange the atoms into arrays and form atomic mirrors, with the flexibility to explore the collective interactions between the atoms for different geometries.

“This collective response in atomic systems has been theoretically investigated for a long time,” said Burgers. “But now, with optical tweezers, we can make geometries that let us experimentally explore this collective regime.”

After demonstrating the mirror effect with his array of atoms, Burgers plans to form an optical cavity from two atomic mirrors, to replace the macroscopic cavity mirrors mentioned above.

“What sets this work apart is the inherently quantum mechanical nature of the 2D plane of atoms,” Burgers explained, “This unique characteristic enables the generation of entanglement within the atomic mirror and between the mirror and other quantum systems.”

Entanglement is the fundamental resource for building what Burgers calls “modular quantum systems,” or systems with multiple quantum computing components, quantum information storage nodes, or quantum sensors connected via entanglement. These distributed systems are essential for the future of quantum computing, communication, and sensing. 

“It’s quite interesting to imagine building a system, atom by atom, that acts like a mirror, but where you have control over each atom’s quantum state. This system can enable quantum operation of both the cavity mirrors and the atom within the cavity, which is impossible using classical dielectric mirrors,” said Burgers. “As a field, we have yet to explore the potential of this ‘all-atomic’ type system. This project provides us with the opportunity to investigate those exciting new possibilities.”