Chiral magnetic photocurrent in Dirac and Weyl materials

Abstract

Circularly polarized light (CPL) can induce an asymmetry between the number of left-and righthanded chiral quasiparticles in Dirac and Weyl semimetals. We show that if the photoresponse of the material is dominated by chiral quasiparticles, the total chiral charge induced in the material by CPL can be evaluated in a model-independent way through the chiral anomaly. In the presence of an external magnetic field perpendicular to the incident CPL, this allows to predict the linear density of the induced photocurrent resulting from the chiral magnetic effect. The predicted effect should exist in any kind of Dirac or Weyl materials, with both symmetric and asymmetric band structure. An estimate of the resulting chiral magnetic photocurrent in a typical Dirac semimetal irradiated by an infrared laser of intensity 5 × 10 6 W/m 2 and a wavelength of λ 10 µm in an external magnetic field B 2 T yields a current J 50 nA in the laser spot of size 50 µm. This current scales linearly with the magnetic field and wavelength, opening up possibilities for applications in photonics, optoelectronics, and THz sensing.

Chiral magnetic effect reveals the topology of gauge fields in heavy-ion collisions

“…[35]. A different way to use the chiral anomaly for the generation of the chiral magnetic current is to use circularly polarized light [36]. The correspondence between the currents induced by the chiral anomaly in different physical systems is shown in the Table 1 below.…”

The Chiral Qubit: quantum computing with chiral anomaly

“…We have thus established that the current circulating in the ring (or in a three-dimensional crystal) is determined by the difference in the Fermi energies of right-and left-handed fermions -the chiral chemical potential. This difference can be controlled through the chiral anomaly by a time-dependent magnetic flux through the ring (in 1 + 1 dimensions) or by circularly polarized photons (in 3 + 1 dimensions) [19].…”

“…In this paper we propose a design of a "chiral qubit" based on this novel quantum phenomenon. The advantages of the proposed qubit architecture stem from the presence of CME at much higher temperatures ∼ 150 K (and potentially at room temperature), and the predicted [19] possibility to manipulate the chiral magnetic current by light with ∼ 10 THz frequency. At the same time, it appears that the Hamiltonian describing the chiral qubit is very similar to the Hamitonian of superconducting qubits, which enables the traditional implementation of quantum gates.…”

Transverse chiral magnetic photocurrent induced by linearly polarized light in mirror-symmetric Weyl semimetals

“…Unlike the helical magnetic photocurrent [16] and chiral magnetic photocurrent [18], this photocurrent is perpendicular to the magnetic field. The symmetry analysis above shows that this photocurrent is not forbidden.…”

“…Strong magnetic fields have been predicted to induce a magnetogyrotropic photogalvanic current in Weyl semimetals with tilted cones, due to the quantization of Landau levels [17]. In mirror-symmetric Dirac and Weyl semimetals, in the presence of a magnetic field, a photocurrent has also been predicted due to chiral anomaly [18]. Circularly polarized light has also been predicted to cause a topologically protected photocurrent through the quantized circular photogalvanic effect in asymmetric Weyl semimetals [19], and a photocurrent parallel to the direction of incident light due to an induced effective magnetic field [20].…”