Abbamonte and Madhavan named EPiQS investigators

Siv Schwink for Illinois Physics
5/28/2020

Moore Foundation grants enable experimental leaps in quantum materials

The Gordon and Betty Moore Foundation, through its Emergent Phenomena in Quantum Systems Initiative (EPiQS), has awarded substantial research funding to two experimental condensed matter physicists at the University of Illinois at Urbana-Champaign. Physics Professors Peter Abbamonte and Vidya Madhavan will receive EPiQS Experimental Investigator awards of $1.6 million each over the next five years.

EPiQS prioritizes high-risk, high-reward fundamental research programs in quantum materials, to foster scientific breakthroughs. EPiQS experimental investigators have the freedom to pursue challenging and novel research directions of the scientists’ own choosing.

Abbamonte and Madhavan are among 20 U.S. scientists to be selected in this, the second cycle of EPiQS experimental investigator awards, joining a collaborative EPiQS community of innovators in quantum materials from the fields of physics, chemistry, and materials science. In addition to the funding, the scientists will get the opportunity to participate in EPiQS investigator symposia, topical workshops, and the QuantEmX (Quantum Emergence Exchange) scientist exchange program.

“The Experimental Investigator awards are the largest grant portfolio within the EPiQS initiative,” notes Amalia Fernandez-Pañella, program officer of the EPiQS Initiative. “We expect that such substantial, stable and flexible support will propel quantum materials research forward and unleash the creativity of the investigators.”

Fox Family Engineering Professor Peter Abbamonte

Illinois Physics Professor Peter Abbamonte. Photo by L. Brian Stauffer, University of Illinois at Urbana-Champaign
Illinois Physics Professor Peter Abbamonte. Photo by L. Brian Stauffer, University of Illinois at Urbana-Champaign
Abbamonte will use his award to develop new spectroscopy instrumentation capable of measuring for the first time the interactions of quantum particles. To date, spectroscopic probes are capable of measuring particles, but not their interactions. However, the most pressing unsolved questions in quantum materials science relate to the interactions of particles, which give rise to all emergent quantum phenomena. If successful, Abbamonte’s new investigative tool, called “coincidence M-EELS,” will provide a more complete understanding of the mechanics underlying superconductivity in a class of materials known as “strange metals.”

“Coincidence M-EELS could reveal, once and for all, the mechanism driving all Fermi surface instabilities, including superconductivity in materials in which its origin is unknown,” Abbamonte asserts.

This project builds on the capabilities of Abbamonte’s M-EELS instrumentation, developed with a first-cycle EPiQS award. Using M-EELS, Abbamonte’s group has already achieved many experimental firsts, including the first successful probe of charge collective modes at nonzero momentum.

The second-cycle EPiQS award will further allow the Abbamonte group to apply its successful M-EELS technique to a profound new set of problems in quantum materials, with emphases on strange metals, axion insulators, and superconductors with fluctuating charge order.

“No experiment has ever observed the ‘axion,’ which is a prediction of quantum field theory and candidate particle for cosmological dark matter,” explains Abbamonte. “This study could finally demonstrate the elusive axion particle and provide a new view on the magnetoelectric properties of topological materials.”

Professor Vidya Madhavan

Illinois Physics Professor Vidya Madhavan. Photo by L. Brian Stauffer, University of Illinois at Urbana-Champaign
Illinois Physics Professor Vidya Madhavan. Photo by L. Brian Stauffer, University of Illinois at Urbana-Champaign
Madhavan will use her grant for two research programs that will advance our understanding of emergent phenomena in quantum materials. In one project, Madhavan’s team will develop new instrumentation that will enable them to measure dynamic changes in the order parameter—the degree of order before and after a phase transition—in greater detail than is possible today.

“The experimental and theoretical understanding of non-equilibrium phases is a wide-open frontier in condensed matter physics,” comments Madhavan. “A looming challenge is to associate measured non-equilibrium phenomena with actual changes in the order parameter, be it charge/spin-order or superconductivity. A new tool that can dynamically stabilize non-equilibrium phases and measure changes at the nanoscale would be significant.”

Madhavan’s new instrument will apply pulses of infrared or terahertz beams of light to induce and dynamically stabilize excitations, which will be combined with scanning tunneling microscopy (STM) to directly visualize the evolution of order parameters in real space. She calls this technique “ph-STM.”

The new instrument will take advantage of cutting-edge technological advances. She notes, “Recent rapid advances in ultrafast lasers and nonlinear crystals, photoconductive antenna technology, and STM technology make this project timely.”

Madhavan’s second project will be to develop new capabilities with “gating” geometry, to study gate-induced phase transitions using STM. Gated-STM is carried out by applying a voltage to a dielectric under the sample.

Madhavan explains, “Gating is a tremendously powerful tool for tuning the properties of quantum materials. This has been proven many times over in generations of remarkable electron-transport experiments. Most gated-transport studies are confined to micron-sized flakes cleaved in air, which is hugely restrictive for STM. Using thin films, we aim to establish gating as a technique that can be reliably used in combination with STM.”

“Combining the gating geometry with film-growth is technically challenging,” Madhavan adds. “The sample holder has to be robust again extreme temperature changes of 1000 K during film growth to 300 mK during measurements. Such extreme temperature changes can lead to electrical contact or shorting problems. This award will enable us to redesign our system to solve these problems.”

About EPiQS

The Moore Foundation’s official announcement of the 2020 EPiQS Experimental Investigators was made on May 28, 2020.

Since 2013, EPiQS has supported an integrated research program that includes materials synthesis, experiment, and theory, and that crosses the boundaries between physics, chemistry and materials science. The second phase of the initiative was kicked off earlier this year with the launch of two major grant portfolios: Materials Synthesis Investigators and Theory Centers.

The twenty newly inaugurated Experimental Investigators were selected through a national competition with an extensive peer-review process. The collective impact of these investigators will produce a more comprehensive understanding of the fundamental organizing principles of complex quantum matter in solids.

About the Moore Foundation

The Gordon and Betty Moore Foundation fosters path-breaking scientific discovery, environmental conservation, patient care improvements and preservation of the special character of the Bay Area. To learn more, visit Moore.org or follow @MooreFound.

 

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