Nonreciprocal gain in non-Hermitian time-floquet systems. Phys. Rev. Lett. 120, 087401 (2018). Article ADS Google Scholar Haldane, F. & Raghu, S. Possible realization of directional optical waveguides in photonic crystals with broken time-reversal symmetry. Phys. Rev. Lett. 100, 013904 (...
Nonreciprocal gain in non-Hermitian time-floquet systems. Phys. Rev. Lett. 120, 087401 (2018). Article ADS Google Scholar Haldane, F. & Raghu, S. Possible realization of directional optical waveguides in photonic crystals with broken time-reversal symmetry. Phys. Rev. Lett. 100, 013904 (...
In the previous chapter, we considered the consequences of breaking inversion symmetry in discrete superlattices. Here, we present examples of phononic structures that break four types of symmetry, namely time-reversal symmetry, parity symmetry, chiral symmetry and particle-hole symmetry. The ...
The peak in the spin susceptibility is consistent with a possible ferromagnetic state at T = 0. The onset of such magnetism would convert the quantum spin Hall to a quantum anomalous Hall effect. While such a symmetry-broken phase typically is accompanied by a gap, we find that the ...
The time-reversal symmetry was broken by applying static magnetic field to the cavity. Depending on the direction of the external magnetic field, one-way topological edge states were excited in the topological cavity. To show the robustness against backscattering, an arbitrarily shaped closed contour...
SYMMETRYBREAKINGWe study the complex Berry phases in non-Hermitian systems with parity-and time-reversal(PT) symmetry.We investigate a kind of two-level system with PT symmetry.We find that the real part of the the complex Berry phases have two quantized values and they are equal to either ...
The essential difference between a TI and a TCI is that the former only requires time-reversal symmetry, such that it remains nontrivial even when all crystalline symmetries are broken. TI does not have LCs, so that the method we use does not apply to SI having zt ∈ odd. To ...
Here we introduce an alternative guiding principle, which we call ‘quasi-symmetry’. This is the situation where a Hamiltonian has exact symmetry at a lower order that is broken by higher-order perturbation terms. This enforces finite but parametrically small gaps at some low-symmetry points in...
b, c). The parity (and mirror) eigenvalue switching between the [Math Processing Error]Γ point and the other high-symmetry points in the BZ indicates the nontrivial topology of the SC with the expanded structure. Fig. 1 Dimensional hierarchy of the higher-order topology. a Schematics of ...
In the previous chapter, we considered the consequences of breaking inversion symmetry in discrete superlattices. Here, we present examples of phononic structures that break four types of symmetry, namely time-reversal symmetry, parity symmetry, chiral symmetry and particle-hole symmetry. The ...