Condensed matter systems, due to their inherent complexity, often have measurable properties whose values are sensitive to experimental details. There are, however, a remarkable set of materials, collectively known as topological phases, which have one or more features that are precisely quantized.
A prominent example of such a phase is the integer quantum Hall effect (IQHE), a phenomenon that arises in two-dimensional systems of electrons in a magnetic field. In the IQHE, a stable (Hall) conductance can be measured that agrees with theoretical predictions better than one part in a billion—this would be equivalent to measuring the distance between New York and Los Angeles to an accuracy of one millimetre! More recently, similar topological features have been observed in systems known as topological insulators.
Our group studies these and other topological phases of matter, as well as more general strongly correlated systems. Some of our recent work explores:
- Driven quantum systems—time-dependent analogues of topological phases with an associated notion of holography.
- Lattice effects on topological phases—we study the effects of a lattice in the weak (quantum Hall) and strong (Chern insulator) regimes.
- Nonsymmorphic crystals—topological aspects of crystals protected by nonsymmorphic symmetries.
- Topological superconductors—we studied the Hall conductivity in a superconducting Rashba system.
- Earlier work—some of our earlier work attempted to classify and discover new topological phases and to study their unique properties.
Please use the links above or the menu on the left to find out more about the research themes of our group and specific research projects.