Steffen Wiedmann

TL;DR: The quantum phase transition at the critical thickness, d = 6.3 nanometers, was independently determined from the magnetic field–induced insulator-to-metal transition, providing experimental evidence of the quantum spin Hall effect.

TL;DR: In this article, the quantum spin Hall effect was observed in HgTe/(Hg,Cd)Te quantum wells with well width d 6.3 nanometers and the residual conductance was independent of sample width, indicating that it is caused by edge states.

TL;DR: Alkali-substitution entails a tunability to the material system in its response to X-rays and structural properties that is most strongly revealed in Rb- substituted compounds whose X-ray sensitivity outperforms other double perovskite-based devices reported.

TL;DR: Large-area high-quality graphene capacitors are used to study behavior of the density of states in this material in zero and high magnetic fields, revealing a number of interesting many-body effects.

TL;DR: It is demonstrated that transport under steady-state illumination is considerably altered at the structural phase transition in the MA compounds, providing advanced insights into the evolution of the crystal structure with decreasing temperature that are essential to interpret the growing interest in investigating the electronic, optical, and photonic properties of lead-halide perovskite materials.