All aperiodic systems display an intrinsic degree of freedom, called the phason, and here it is shown that the phason space for twisted bilayered systems is a 2-torus. As a consequence, these systems host the physics of 4-dimensional integer quantum Hall effect, which can be accessed by simply sliding the layers relative to each other.
- Matheus I. N. Rosa
- Massimo Ruzzene
- Emil Prodan
