1. Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
2. Department of Applied Physics, New Haven, Connecticut 06520, USA
3. Center for Research on Interface Structures and Phenomena (CRISP), Yale University, New Haven, Connecticut 06520, USA
4. Unité Mixte de Physique, CNRS, Thales, Université Paris Saclay, 91767 Palaiseau, France
5. Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854-8019, USA
6. Department of Applied Physics, Department of Physics, and Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06520, USA