Freek Massee
     Laboratoire de Physique des Solides, CNRS

Research

My research interests span a wide range of correlated electron systems in the field of condensed matter physics, including high (and low) temperature superconductors, heavy fermion systems, colossal magnetoresistant manganites, ... In addition to low temperature, high energy resolution scanning tunneling microscopy, I recently started to develop a high frequency scanning tunneling microscope to measure - among other things - shot-noise at the atomic scale.

Shot-noise scanning tunneling microscopy

To access the dynamics at the atomic scale of correlated electron systems I am setting up a shot-noise compatible scanning tunneling microscope at the Laboratoire de Physique des Solides.
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Heavy fermion superconductivity

The discovery of superconductivity in heavy fermion materials marked the birth of unconventional superconductivity. The Cooper pairing mechanism of heavy-fermion superconductors, while long hypothesized as due to spin fluctuations, has not been determined. Using Bogoliubov quasiparticle interference (QPI) imaging we studied the momentum space (k-space) structure of the superconducting energy gap Δ(k) that encodes specifics of this pairing mechanism.
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Iron based superconductivity

Irradiation of superconductors with high energy heavy ions can be used to create nanoscale defects that act as deep pinning potentials for vortices. Using scanning tunneling microscopy, we study the atomic scale effect of the irradiation damage on superconductivity and vortex pinning.
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Colossal magnetoresistant manganites

Using a combination of atomic scale scanning tunneling microscopy and spectroscopy, and small spot size (100 μm) angle resolved photoemission spectroscopy, we study the ground state of the bilayered colossal magnetoresistant manganite (La,Sr)N+1MnNO3N+1.
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