• Transport of heat, charge and spin in solids
• Thermoelectricity, thermodynamics
• Physics of narrow-gap semiconductors

Research interests

Experimental investigation of electron, phonon and spin transport properties, semiconductor, semimetals, topological and magnetic materials and nanostructures. Contributions:

• Phonon physics. Phonons in ferroelectric materials are affected by an external electric field.  This opens the field of study of mixed polarization and heat transport, polarization caloritronics. Phonon transport is also modulated by a magnetic field in diamagnets.
• Goniopolar materials exhibit simultaneous n- and p-type behavior by the same charge carriers.  They enable the construction of transverse thermoelectric generators that have no electrical contacts at their hot side, and mostly eliminate efficiency losses in contact resistances.
• Thermal properties of electrons in topological and quantum materials.  The gravitational anomaly (or thermal chiral anomaly) is a new way for electrons to carry heat in Weyl semimetals, in which electrons are massless but chiral.
• Mixed heat and spin transport, spin caloritronics: The spin-Seebeck effect in magnetic and narrow-gap semiconductors, and the magnon-drag effect in metals and semiconductors.
• Thermoelectricity.
  • Resonant dopants increase the thermoelectric figure of merit.
  • Large thermopowers in quantum wires due to size-quantization.
• Geometrical effects in the transport of heat and charge in narrow-gap semiconductors, commercialized in magnetic position sensors used on crank and camshafts by General Motors.

Selected publications

• Wooten, B. L., Iguchi, R., Tang, P., Kang, J. S., Uchida, K. Bauer, G. E. W and Heremans, J.P.“Electric field–dependent phonon spectrum and heat conduction in ferroelectrics”, Science Advances 9, eadd7194 (2023)
• Uchida, K. and Heremans, J.P. “Thermoelectrics: from Longitudinal to Transverse”, Joule, 6, 1–6 (2022)
• Vu, D.D., Zhang, W. Şahin, C., Flatté, M.E. Trivedi, N. and Heremans, J.P. “Thermal chiral anomaly in the magnetic-field induced ideal Weyl phase of Bi1-xSbx topological insulators”, Nature Materials 20,1525–1531 (2021)
• Zheng, Y., Lu, T., Polash, M. H., Rasoulianboroujeni, M., Liu, N., Manley, M. E., Deng, Y., Sun, P. J., Chen, X. L., Hermann, R. P. , Vashaee, D. , Heremans, J. P. and Zhao, H.  “Paramagnon drag in high thermoelectric figure of merit Li-doped MnTe“, Science Advances,5, eaat9461, (2019)
• He, B., Wang, Y., Arguilla, M. Q., Cultrara, N. D., Scudder, M. R., Goldberger, J. E., Windl, W., and Heremans, J. P., “The Fermi Surface Geometrical Origin of Axis-Dependent Conduction Polarity in Layered Materials,” Nature Materials 18 568-572 (2019)
• Heremans, J. P., Cava, R. J., and Samarth, N. (2017), “Tetradymites as Thermoelectrics and Topological Insulators,” Nature Reviews Materials 2 17049 (2017)
• Jin, H., Restrepo, O. D., Antolin, N., Boona, S. R., Windl, W., Myers, R. C., and Heremans, J. P., “The Phonon-induced Diamagnetic Force and its Effect on the Lattice Thermal Conductivity,” Nature Materials 14, 601-606 (2015)
• Boona, S. R., Myers, R. C., and Heremans, J. P., “Spin Caloritronics,” Energy Environ. Sci., 7, 885-910 (2014)
• Jaworski, C. M., Myers, R. C., Johnston-Halperin, E., and Heremans, J. P., “Giant Spin Seebeck Effect in a Non magnetic Material,” Nature 487, 210-213 (2012)
• Jaworski, C. M., Yang, J., Mack, S., Awschalom, D. D., Heremans, J. P., and Myers, R. C., “Observation of the Spin-Seebeck Effect in a Ferromagnetic Semiconductor,” Nature Materials 9 898-903 (2010)
• Heremans, J. P., Jovovic, V., Toberer, E. S., Saramat, A., Kurosaki, K., Charoenphakdee, A., Yamanaka, S., and Snyder, G. J., “Enhancement of Thermoelectric Efficiency in PbTe by Distortion of the Electronic Density of States,” Science 321 554 -558 (2008); doi.org/10.1126/science.1159725