The idea
Empty space is not empty. Even with every light source switched off, an electromagnetic field still fluctuates in any volume — the vacuum field. Normally it is far too weak to matter. But if you squeeze light into a small enough box, the vacuum field inside that box becomes enormous.
That is what our cavities do. Using hyperbolic polaritons — light bound to the lattice vibrations of a layered crystal — we confine mid-infrared light to volumes vastly smaller than its own wavelength. In that regime the vacuum stops being a background and becomes an ingredient: it couples to the electrons and phonons of the material strongly enough to change what the material is.
The prize is a form of control with no laser in it. Not driving a material and watching it relax, but placing it in an environment that quietly rewrites its ground state, and leaving it there.
Central questions
- How strongly can matter be coupled to a field that is not there — and what breaks first when we push past it?
- Can vacuum fields change a phase of matter: its conductivity, its magnetism, its order?
- What does light–matter interaction look like when light and matter are both quantum, and neither can be treated as a background for the other?
- How far can light be confined before the very idea of a photon in a cavity stops being useful?
Where this goes
We want cavity engineering to become a standard tool for materials physics — a knob as ordinary as temperature or pressure, but acting on the quantum electrodynamic environment instead of the lattice. A material placed in the right cavity should acquire properties it does not have on its own, reversibly and by design.
Getting there means pushing confinement further than anyone currently does, and learning to read out the result inside a structure so small that most probes cannot see into it. Both halves are experiments in their own right.
Capabilities and methods
| Extreme light confinement | Polaritonic cavities built from layered crystals, compressing mid-infrared light far below its free-space wavelength. |
| Hyperbolic polaritons | Light bound to lattice vibrations, propagating with strongly directional dispersion — the mechanism that makes the confinement possible. |
| High-field mid-IR ultrafast laser | For high-field and Floquet experiments: dressing a material with intense light and asking what its band structure becomes. |
| Cryogenic transport | Electrical readout at low temperature, where the effects we are looking for are not washed out by thermal noise. |
| Time-resolved exciton spectroscopy | Visible-range, ultrafast — watching how coupled excitations actually evolve rather than inferring it from averages. |