Stretchable Photonic ‘Fermi Arcs’ in Twisted Magnetized Plasma

Weyl points, three‐dimensional linear bulk bands crossings possessing intrinsic helicities, are counterparts of magnetic monopoles in the momentum space. One of the most important features of Weyl semimetals is the presence of topologically protected non‐trivial surface states at the boundary that connect between Weyl points of opposite charges. In condensed matter physics, these surface states are called Fermi arcs whose length measures the topological strength of the system. Here we theoretically show that photonic ‘Fermi arcs’ can exist at the interface between two magnetized plasma under static bias magnetic fields of different orientations, i.e. a twisted configuration, whereas the length of the ‘Fermi arcs’ can be arbitrarily stretched by varying the relative orientation and intensities of two static bias magnetic fields. Interestingly, the ‘Fermi arcs’ join two Weyl points of the same sign but residing on different side of the interface. Our work gives insight to the connectivity of ‘Fermi arcs’ between two topological semimetals and could open gateway towards tunable photonic topological systems.