John Neumeier
Montana State University, MT·Physics
Electrons in most metals are packed densely. When only a few are present, they can act together in unusual quantum ways that physicists rarely get to study.
- Fields
Physics
Materials Science
- Topics
superconductivity
condensed matter physics
quantum materials
- Grants
- 2 known grants, through Feb 2030
What they work on
- Track how a quasi-one-dimensional crystal changes from a metallic superconductor to a non-superconducting insulator as its charge-carrier density is varied. Single crystals will be measured for electrical, thermal and magnetic properties and for thermal expansion.
- Explore whether the insulating, non-superconducting state at the lowest electron densities represents Bose-Einstein condensation of electrons, in which many electrons share one quantum state.
- Use neutron diffraction, which scatters neutrons off a crystal to reveal magnetic order, to test for a spin-density wave in the crossover between the superconducting and insulating regimes.
- Synthesize and grow single crystals of new transition-metal oxides and chalcogenides to discover new materials, new physical behaviors and new quantum states.
- Recruit and mentor graduate fellows for projects on ocean oxygen minimum zones, gravitational waves from white dwarf stars, and methane production by methanogens from mangroves and Yellowstone hot springs.
More about the research
The main research project here examines a material in which tuning the number of mobile electrons switches it between two states. At one end it is a metal that superconducts, carrying electric current with zero resistance. At the other end it is an insulator that does not superconduct. Understanding this crossover could reveal new physics of electrons in low-density, low-dimensional settings. A second award will support a graduate fellowship program at Montana State University spanning chemistry, physics and biology.
Why it matters
This is mainly basic physics. Learning how electrons behave collectively at very low density adds to the understanding of superconductivity and unusual quantum states. New oxide and chalcogenide materials could reveal behaviors that eventually feed into new technologies. The fellowship program aims to build research capacity in Montana and help meet the state's need for a STEM workforce in its growing high-technology economy.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
Tej Nath Lamichhane
University of Central Oklahoma, OK·Materials Science
Synthesize new cerium compounds containing transition metals and heavy chalcogen elements such as selenium or tellurium, using crystal growth and solid-state reactions, to search for unusual electronic states.
Yusong Bai
Brown University, RI·Physics·Early-career
Establish correlated electronic states and electric-field-controlled metal-insulator transitions in heterostructures where ordered nanocrystal superlattices impose periodic potentials on atomically thin materials, using low-temperature electrical transport.
Vladyslav Kozii
Carnegie Mellon University, PA·Physics·Early-career
Develop and analyze theoretical pairing mechanisms for superconductors with very low electron density, determining when superconductivity can survive as carrier density approaches zero.
The school
Montana State University: 15 labs on PI Pages, $258M a year on research, 85 research doctorates a year.
Reach out
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