Transverse-Electric Cherenkov Radiation for TeV-Scale Particle Detection.

Cherenkov radiation enables high-energy particle identification through its velocity-dependent emission angle, yet conventional detectors fail to detect momenta beyond tens of GeV/c owing to the absence of natural materials with near-unity refractive indices. The limitation is overcome by demonstrating directional Cherenkov radiation from transverse-electric (TE) graphene plasmons, excited by a swift charged particle travelling above suspended monolayer graphene. Crucially, TE graphene plasmons exhibit a near-unity mode index, sustaining high sensitivity of the Cherenkov angle to relativistic velocities up to the TeV/c regime. The radiation further maintains exceptional robustness against particle-graphene separation changes, enabled by the TE mode's low transverse decay rate. This ultracompact platform is electrically tunable, allowing on-chip, reconfigurable detection of ultrahigh-energy particles and extending measurable momenta by two orders of magnitude beyond existing detectors.