PT-Symmetric Cladding Layers for high-Q Brewster Modes and Embedded Eigenstates

Epsilon near near-zero (ENZ) materials have been raising significant interest in various
research areas. Rich concepts such as photonic doping an d supercoupling featuring ENZ
materials have been reported. ENZ materials have been proven to be instrumental to ach ieve
embedded eigenstates, or self self-sustained electromagnetic resonances in open structures with
momentum compatible with the radiation conti nuum. However, unavoidable absorption in
realistic ENZ materials results in a finite lifetime of these modes, and de cay to radiation. Here,
we present a strategy to tackle the losses of ENZ materials in order to produce unbounded high high-Q resonances with the use of PT -symmetry and the concept of suppressed leakage. These results
pave the way to efficient light trapping an d sensing applications with realistic ENZ materials.