1:30 pm MCP 201
Quantum oscillation in a 2d Fermi liquid from coadjoint-orbit bosonization.
In weak magnetic fields B, a metal’s magnetization oscillates with 1/B and displays an essential singularity at B→0, beyond the reach of conventional many-body response theory. We develop a bosonized effective field theory for a two-dimensional Fermi surface in weak B using the coadjoint-orbit formulation of nonlinear bosonization. The resulting action contains topological terms that have been overlooked. Upon proper quantization, the theory yields thermal and magnetic responses of the Fermi surface, including quantum oscillations. We show that these oscillations are intrinsically topological, arising from a specific topological term in the action. Applied to two-dimensional Fermi liquids, our framework resolves the long-standing issue of the breakdown of the Lifshitz–Kosevich formula.