Kevin P. Nuckolls

Research interests

Contemporary quantum materials research is broadly guided by two major themes: electronic correlation effects and topologically protected properties. Correlation effects result from interactions among an Avogadro number (~1023) of electrons, which produce exotic collective phases of matter which cannot be understood as the sum of their parts. Topological properties are perplexingly immutable qualities of materials that are derived from geometric qualities of a material’s electronic energy bands. My research focuses on how these two paradigms give rise to new and unusual material properties, some of which may be useful for next-generation quantum technological applications.

Strongly Correlated Materials

Electronic correlation effects in materials produce complex collective behaviors of electrons that cannot be reduced to the sum of its parts.

In magic-angle graphene, we discovered a cascade of correlated metallic phases with sharp spectroscopic signatures, which form the high-temperature parent phase from which more fragile low-temperature phases insulating and superconducting phase are stabilized. We also used atomic-scale imaging methods to identify the nature of particular quantum ground states in MATBG.

Quantum textures of the many-body wavefunctions in magic-angle graphene

KPN*, R. L. Lee*, M. Oh*, D. Wong*, T. Soejima* et al.

Nature 620, 525-532 (2023).

[link] [preprint]

Cascade of electronic transitions in magic-angle twisted bilayer graphene

D. Wong*, KPN*, M. Oh* et al.

Nature 582, 198-202 (2020).

[link] [preprint]

Superconducting Materials

Superconductivity is an extraordinary phase of matter made of trillions of trillions of electrons that collaborate to create a macroscopic, frictionless quantum fluid made of pairs of electrons. In this cooperative phase of matter, superconducting materials conduct electricity without energy loss.

In magic-angle graphene, we established key spectroscopic signatures of unconventional superconductivity that are irreconcilable with conventional theories.

Evidence for unconventional superconductivity in twisted bilayer graphene

M. Oh*, KPN*, D. Wong* et al.

Nature 600, 240-245 (2021).

[link] [preprint]

Strong electron-phonon coupling in magic-angle twisted bilayer graphene

C. Chen*, KPN* et al.

Nature 636, 342-347 (2024).

[link] [preprint]

Topological Materials

Topologically protected properties of materials are robustly unchangeable against continuous deformations, and are derived from intrinsically geometric properties of the quantum physics that describes these materials.

In magic-angle graphene, we uncovered a sequence of magnetic topological insulators that break time-reversal symmetry spontaneously. These highly tunable states are rare examples of correlated topological phases of matter.

Strongly correlated Chern insulators in magic-angle twisted bilayer graphene

KPN*, M. Oh*, D. Wong* et al.

Nature 588, 610-615 (2020).

[link] [preprint]

Spectroscopy of the fractal Hofstadter energy spectrum

KPN*, M. G. Scheer*, D. Wong*, M. Oh* et al.

Nature 639 60-66 (2025).

[link] [preprint]

Atomic-Scale Imaging & Spectroscopy

The scanning tunneling microscope (STM) is a powerful tool capable of studying materials with atomic-scale spatial resolution and unmatched energy resolution.

For the first two years of my PhD, I helped build a millikelvin temperature STM facility from scratch, which my teammates and I used for all of our experiments on magic-angle graphene.

A modular ultra-high vacuum millikelvin scanning tunneling microscope

D. Wong*, S. Jeon*, KPN*, D. Wong* et al.

Rev. Sci. Instrum. 91, 023703 (2020)

[link] [preprint]

2D Material Device Fabrication

These devices consist of stacks of 2D materials that have been exfoliated layer-by-layer from bulk crystals, mixed and matched, twisted and stacked into one, synergistic super materials with newly engineered / emergent electronic properties.

Many new techniques for creating electronic devices from these atomically thin layers have been developed in the past decade, and have enabled us to design the properties of quantum materials on-demand.

MaterialS Synthesis & Advanced Transport / THermodynamic Measurement

Coming Soon!