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Scientists in Brookhaven's Condensed Matter Physics & Materials Science Department study basic, theoretical and applied aspects of materials, their utilization, and their electronic, physical, mechanical, and chemical properties in relation to their structure. 

The field of Condensed Matter Physics and Materials Science integrates the knowledge and tools of chemistry and physics with the principles of engineering to understand and optimize the behavior of materials, as well as to create new and improved materials to help fulfill the missions of the Department of Energy.

  1. JAN

    28

    Tuesday

    Condensed-Matter Physics & Materials Science Seminar

    "Effect of Zeeman coupling on the Majorana vortex modes in iron-based topological superconductors"

    Presented by Pouyan Ghaemi, The City College of New York

    1:30 pm, ISB Bldg. 734, Conf. Rm. 201 (upstairs)

    Tuesday, January 28, 2020, 1:30 pm

    Hosted by: Peter D. Johnson

    In the superconducting regime of FeTe(1−x)Sex, there exist two types of vortices which are distinct by the presence or absence of zero energy states in their core. To understand their origin,we examine the interplay of Zeeman coupling and superconducting pairings in three-dimensional metals with band inversion. Weak Zeeman fields are found to suppress the intra-orbital spin-singlet pairing, known to localize the states at the ends of the vortices on the surface. On the other hand, an orbital-triplet pairing is shown to be stable against Zeeman interactions, but leads to delocalized zero-energy Majorana modes which extend through the vortex. In contrast, the finite-energy vortex modes remain localized at the vortex ends even when the pairing is of orbital-triplet form. Phenomenologically, this manifests as an observed disappearance of zero-bias peaks within the cores of vortices upon increase of the applied magnetic field. The presence of magnetic impurities in FeTe(1−x)Sex, which are attracted to the vortices, would lead to such Zeeman-induced delocalization of Majorana modes in a fraction of vortices that capture a large enough number of magnetic impurities. Our results provide a possible explanation to the dichotomy between topological and non-topological vortices recently observed in FeTe(1−x)Sex.

Condensed Matter Theory

Conducts basic research over a wide swath of theoretical physics, ranging from strongly correlated electrons to first principle electronic structure theory.  

Neutron Scattering

Studies the role of antiferromagnetism in high-temperature superconductors.  The interaction of charge carriers with magnetic moments is of critical importance but remains a challenge to understand. .

X-Ray Scattering

Carries out basic studies of the structural, electronic and magnetic properties of condensed matter systems using synchrotron-based x-ray scattering techniques. .

comscope logo

The Center for Computational Material Spectroscopy and Design develops, advances, and shares a powerful and user-friendly software suite called Comsuite to accelerate the discovery, analysis, and design of functional strongly correlated materials—the basis for next generation technologies.

Electron Microscopy and Nanostructure

Utilizes advanced electron microscopy techniques to study nanoscale structure and defects that determine the utility of functional materials, such as superconductors, multiferroics, and other energy related systems including thermoelectrics, photovoltaics, and batteries.

Oxide Molecular Beam Epitaxy

Addresses key open questions in HTS physics such as the dimensionality of the HTS phenomenon, the spin and charge of free carriers, the nature of the superconducting transition, the role of charge stripes (if any) in the HTS state, the nature of the overdoped metallic state, and more.

Spectroscopic Imaging

Span a wide range of quantum matter systems, including superconductors, superfluids, supersolids, electronic liquid crystals, topological insulators superconductors & superfluids, heavy fermions, and spin liquids. Throughout, the focus is on development of innovative techniques and approaches to each problem.

Advanced Energy Materials

Studies both the microscopic and macroscopic properties of complex and nano-structured materials with a view to understanding and developing their application in different energy related technologies

Electron Spectroscopy

Explores the electronic structure and electrodynamics of topological insulators and strongly correlated electron systems, with particular attention to emergent phenomena, such as superconductivity and magnetism, using angle-resolved photoemission (ARPES) and optical spectroscopy.

The Condensed Matter Physics and Materials Science Department is part of Brookhaven National Laboratory's Energy Sciences Directorate.