Giant topological longitudinal circular photo-galvanic effect in the chiral multifold semimetal CoSi

  title={Giant topological longitudinal circular photo-galvanic effect in the chiral multifold semimetal CoSi},
  author={Zhuoliang Ni and K. L. Wang and Yang Zhang and Oscar Pozo and B. Xu and X. F. Han and Kaustuv Manna and Johnpierre Paglione and Claudia Felser and Adolfo G. Grushin and Fernando de Juan and Eugene J. Mele and Liang Wu},
  journal={Nature Communications},
The absence of mirror symmetry, or chirality, is behind striking natural phenomena found in systems as diverse as DNA and crystalline solids. A remarkable example occurs when chiral semimetals with topologically protected band degeneracies are illuminated with circularly polarized light. Under the right conditions, the part of the generated photocurrent that switches sign upon reversal of the light’s polarization, known as the circular photo-galvanic effect, is predicted to depend only on… 

Suppression of second-harmonic generation from linear bands in the topological multifold semimetal RhSi

Baozhu Lu, ∗ Sharareh Sayyad, ∗ Miguel Ángel Sánchez-Mart́ınez, Kaustuv Manna, 4 Claudia Felser, Adolfo G. Grushin, † and Darius H. Torchinsky ‡ Department of Physics, Temple University,

Hierarchy of quasisymmetries and degeneracies in the CoSi family of chiral crystal materials

  • Lunhui HuChunyu Guo B. Andrei Bernevig
  • Physical Review B
  • 2023

Fundamental laws of chiral band crossings: local constraints, global constraints, and topological phase diagrams

We derive two fundamental laws of chiral band crossings: (i) a local constraint relating the Chern number to phase jumps of rotation eigenvalues; and (ii) a global constraint determining the number

Helicity-dependent Ultrafast Photocurrents in Weyl Magnet Mn$_3$Sn

We present an optical pump-THz emission study on non-collinear antiferromagnet Mn$_3$Sn. We show that Mn$_3$Sn acts as a source of THz radiation when irradiated by femtosecond laser pulses. The

Visualizing Higher-Fold Topology in Chiral Crystals

Novel topological phases of matter are fruitful platforms for the discovery of unconventional electromagnetic phenomena. Higher-fold topology is one example, where the low-energy description goes

Transverse circular photogalvanic effect associated with Lorentz-violating Weyl fermions

because of the Lorentz-symmetry breaking in condensed matter physics. Different from longitudinal CPGE in Weyl semimetal which only depends on the Chern number, we show that transverse CPGE has much

Photocurrent as a multiphysics diagnostic of quantum materials

The photoexcitation life cycle from incident photon (and creation of photoexcited electron–hole pair) to ultimate extraction of electrical current is a complex multiphysics process spanning across a

Recent progress in the theory of bulk photovoltaic effect

The bulk photovoltaic effect (BPVE) occurs in solids with broken inversion symmetry and refers to DC generation due to uniform illumination, without the need of heterostructures or interfaces, a



Mechanical Stretch Inhibits Oxidized Low Density Lipoprotein-induced Apoptosis in Vascular Smooth Muscle Cells by Up-regulating Integrin αVβ3 and Stablization of PINCH-1*

Findings provided experimental evidence that mechanical stretch acted as a survival factor in the arches of aortas and prevented VSMC from apoptosis via a mechanism that involves αVβ3 integrin expression, stabilization of PINCH-1, and remodeling of the cytoskeleton.

Quantized Photocurrents in the Chiral Multifold Fermion System RhSi

The rapid pace of discovery of new classes of Weyl semimetals is driving a search for properties that derive from their unique bandstructure topology. One of the most striking of the predicted

Chiral terahertz wave emission from the Weyl semimetal TaAs

Findings provide a design concept for creating chiral photon sources using quantum materials and open up new opportunities for developing ultrafast opto-electronics using Weyl physics.

Terahertz Radiation from Semiconductors

We provide a review of the different schemes for generating terahertz (THz) radiation using photoconductive emitters excited by femtosecond lasers. The discussion is concerned principally with

Frequency-resolved multifold fermions in the chiral topological semimetal CoSi

We report the optical conductivity in the linear-response regime of the chiral topological semimetal CoSi, predicted to host elusive topological quasiparticles known as multifold fermions. We find

Optical signatures of multifold fermions in the chiral topological semimetal CoSi

The presence and the energy range of various exotic multifold quasiparticles in the optical responses are revealed and experimental evidence for the realization of fourfold spin-3/2 fermions is provided, which were not directly observed previously.

Linear and nonlinear optical responses in the chiral multifold semimetal RhSi

Chiral topological semimetals are materials that break both inversion and mirror symmetries. They host interesting phenomena such as the quantized circular photogalvanic effect (CPGE) and the chiral

Helicity-dependent photocurrents in the chiral Weyl semimetal RhSi

Measurements of CPGE in the chiral Weyl semimetal RhSi are reported, revealing a C PGE response in an energy window that closes at 0.65 eV, in agreement with the predictions of density functional theory.

Quasiparticle interference evidence of the topological Fermi arc states in chiral fermionic semimetal CoSi

Scanning tunneling microscopy/spectroscopy is used to investigate quasiparticle interference at various terminations of a CoSi single crystal and provides strong evidence that CoSi hosts the unconventional chiral fermions and the extensive Fermi arc states.

Expression of CCR7 in multiple sclerosis: Implications for CNS immunity

Analysis of the expression of CCR7 in the CNS of patients with multiple sclerosis suggested that the efferent limb of CNS immunity is executed by central‐memory T cells, which enter CSF directly from the circulation.