Lattice and spin dynamics is crucial for understanding many material properties such as thermal transportation, thermal expansion, and phase transformation with many important science and engineering applications in energy materials, photonics materials, structural materials, and nano-devices.

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Magnon-phonon interaction

Spin waves and phonons are strongly coupled in many ferromagnetic and antiferromagnetic structures.

Application: controlling heat flow on nanoscale, manipulating spin coherence

Supported by: Thermal Transport Process Program, CBET, NSF

Phonons in low dimension

Lattice dynamics is significantly affected by the dimension of materials though phonon confinement and structure modification. We investigate the phonons in 2-D (thin films, thin superlattices), 1-D (nanothreads), and 0-D (quantum points, nanoparticles).

Application: photonics materials, structure materials

Thermal transport under high pressure

We study the transport in materials under these extreme environments for energy applications and phonon engineering.

Application: thermoelectrics, phonon engineering, photonics materials, vdW materials 

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Interfacial thermal transport

We study the effects of phonon anharmonicity on the interfacial thermal conductance.

Application: power electronics

Phonon engineering

Lattice thermal transport can be suppressed by phonon nesting, resonance, nanostructure, doping, and many other approaches

Application: thermoelectrics, thermal management

Negative thermal expansion

Exotic phonons may induce negative thermal expansion in structural materials through anharmonicity.

Application: controlling the thermal expansion of structural materials

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Phonon anhamonicity and lifetime

Anharmonicity of bulk or low-dimension materials (metals, alloys, oxides, …) due to phonon-phonon interactions can be probe by their phonon Grüneisen parameters and lifetime.

Application: correlate anharmonicity and their thermodynamical effects

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Magnetic frustration

Frustrated magnetic ordering in antiferromagnetic materials allow abnormal spin fluctuations and competing ordering.

Applications: spintronics