- Open Access
Circular Dichroism on the Edge of Quantum Hall Systems: From Many-Body Chern Number to Anisotropy Measurements
Phys. Rev. Lett. 135, 266603 – Published 24 December, 2025
DOI: https://doi.org/10.1103/6d6n-3trh
Abstract
Quantum Hall states are characterized by a topological invariant, the many-body Chern number, which determines their quantized Hall conductivity. This invariant also emerges in circular dichroic responses, namely, by applying a circular drive and comparing excitation rates for opposite orientations. This work explores the dichroic response of confined, isolated quantum Hall systems, where bulk and edge contributions cancel exactly: When the edge response is properly isolated, the circular dichroic signal becomes quantized, serving as a direct and elegant probe of the many-body Chern number encoded in the edge physics. We demonstrate that this quantized edge response is entirely captured by low-energy chiral edge modes, allowing for a universal description of this effect based on Wen’s edge theory. Its low-energy nature implies that the quantized edge response can be distinguished from the bulk response in the frequency domain. The edge response is also shown to be a sensitive diagnostic of geometric features. This opens the possibility of characterizing the shape of quantum Hall droplets through edge spectroscopic measurements, without requiring knowledge of the system’s boundary profile. We illustrate our findings using realistic models of integer and fractional Chern insulators, with different edge geometries, and propose detection schemes suitable for ultracold atoms.
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References (94)
- S. M. Girvin, The quantum Hall effect: Novel excitations and broken symmetries, in Aspects Topologiques de la Physique en Basse Dimension. Topological Aspects of Low Dimensional Systems: Session LXIX. 1998 (Springer, New York, 2002), pp. 53–175.
- D. J. Thouless, M. Kohmoto, M. P. Nightingale, and M. den Nijs, Quantized Hall conductance in a two-dimensional periodic potential, Phys. Rev. Lett. 49, 405 (1982).
- Q. Niu, D. J. Thouless, and Y.-S. Wu, Quantized Hall conductance as a topological invariant, Phys. Rev. B 31, 3372 (1985).
- G. E. Volovik, The Universe in a Helium Droplet (Oxford University Press, Oxford, 2003), Vol. 117.
- B. A. Bernevig, Topological Insulators and Topological Superconductors (Princeton University Press, Princeton, NJ, 2013).
- M. Z. Hasan and C. L. Kane, Colloquium: Topological insulators, Rev. Mod. Phys. 82, 3045 (2010).
- X.-L. Qi and S.-C. Zhang, Topological insulators and superconductors, Rev. Mod. Phys. 83, 1057 (2011).
- N. R. Cooper, J. Dalibard, and I. B. Spielman, Topological bands for ultracold atoms, Rev. Mod. Phys. 91, 015005 (2019).
- T. Ozawa, H. M. Price, A. Amo, N. Goldman, M. Hafezi, L. Lu, M. C. Rechtsman, D. Schuster, J. Simon, O. Zilberberg, and I. Carusotto, Topological photonics, Rev. Mod. Phys. 91, 015006 (2019).
- F. Schlawin, D. M. Kennes, and M. A. Sentef, Cavity quantum materials, Appl. Phys. Rev. 9, 011312 (2022).
- J. Bloch, A. Cavalleri, V. Galitski, M. Hafezi, and A. Rubio, Strongly correlated electron–photon systems, Nature (London) 606, 41 (2022).
- Z. Bacciconi, H. Xavier, I. Carusotto, T. Chanda, and M. Dalmonte, Theory of fractional quantum Hall liquids coupled to quantum light and emergent graviton-polaritons, Phys. Rev. X 15, 021027 (2025).
- L. Wu, M. Salehi, N. Koirala, J. Moon, S. Oh, and N. Armitage, Quantized Faraday and Kerr rotation and axion electrodynamics of a 3D topological insulator, Science 354, 1124 (2016).
- F. De Juan, A. G. Grushin, T. Morimoto, and J. E. Moore, Quantized circular photogalvanic effect in Weyl semimetals, Nat. Commun. 8, 15995 (2017).
- D. T. Tran, A. Dauphin, A. G. Grushin, P. Zoller, and N. Goldman, Probing topology by “heating”: Quantized circular dichroism in ultracold atoms, Sci. Adv. 3, e1701207 (2017).
- J. Ahn, G.-Y. Guo, N. Nagaosa, and A. Vishwanath, Riemannian geometry of resonant optical responses, Nat. Phys. 18, 290 (2022).
- A. Kruchkov and S. Ryu, Spectral sum rules reflect topological and quantum-geometric invariants, arXiv:2312.17318.
- I. Souza and D. Vanderbilt, Dichroic -sum rule and the orbital magnetization of crystals, Phys. Rev. B 77, 054438 (2008).
- T. Morimoto, Y. Hatsugai, and H. Aoki, Optical Hall conductivity in ordinary and graphene quantum Hall systems, Phys. Rev. Lett. 103, 116803 (2009).
- B. M. Fregoso, R. A. Muniz, and J. E. Sipe, Jerk current: A novel bulk photovoltaic effect, Phys. Rev. Lett. 121, 176604 (2018).
- A. Bouhon, A. Timmel, and R.-J. Slager, Quantum geometry beyond projective single bands, arXiv:2303.02180.
- Y. Onishi and L. Fu, Fundamental bound on topological gap, Phys. Rev. X 14, 011052 (2024).
- W. J. Jankowski, A. S. Morris, A. Bouhon, F. N. Ünal, and R.-J. Slager, Optical manifestations and bounds of topological euler class, Phys. Rev. B 111, L081103 (2025).
- T. Ozawa and N. Goldman, Extracting the quantum metric tensor through periodic driving, Phys. Rev. B 97, 201117(R) (2018).
- C. Repellin and N. Goldman, Detecting fractional Chern insulators through circular dichroism, Phys. Rev. Lett. 122, 166801 (2019).
- P. W. Klein, A. G. Grushin, and K. Le Hur, Interacting stochastic topology and Mott transition from light response, Phys. Rev. B 103, 035114 (2021).
- K. Le Hur, Global and local topological quantized responses from geometry, light, and time, Phys. Rev. B 105, 125106 (2022).
- O. Pozo, C. Repellin, and A. G. Grushin, Quantization in chiral higher order topological insulators: Circular dichroism and local Chern marker, Phys. Rev. Lett. 123, 247401 (2019).
- T. Ozawa and N. Goldman, Probing localization and quantum geometry by spectroscopy, Phys. Rev. Res. 1, 032019(R) (2019).
- M. Schüler, U. De Giovannini, H. Hübener, A. Rubio, M. A. Sentef, T. P. Devereaux, and P. Werner, How circular dichroism in time- and angle-resolved photoemission can be used to spectroscopically detect transient topological states in graphene, Phys. Rev. X 10, 041013 (2020).
- M. Schüler, U. De Giovannini, H. Hübener, A. Rubio, M. A. Sentef, and P. Werner, Local Berry curvature signatures in dichroic angle-resolved photoelectron spectroscopy from two-dimensional materials, Sci. Adv. 6, eaay2730 (2020).
- R. L. Klees, G. Rastelli, J. C. Cuevas, and W. Belzig, Microwave spectroscopy reveals the quantum geometric tensor of topological Josephson matter, Phys. Rev. Lett. 124, 197002 (2020).
- P. Molignini, B. Lapierre, R. Chitra, and W. Chen, Probing Chern number by opacity and topological phase transition by a nonlocal Chern marker, SciPost Phys. Core 6, 059 (2023).
- N. Goldman and T. Ozawa, Relating the Hall conductivity to the many-body Chern number using Fermi’s Golden rule and Kramers-Kronig relations, C.R. Phys. 25, 289 (2024).
- J. Kim, D. Kim, D. E. Kim, and A. Chacón, Circular dichroism in Floquet Chern insulator via high-order harmonics spectroscopy, J. Phys. Condens. Matter 36, 035701 (2023).
- L. Asteria, D. Tran, T. Ozawa, M. Tarnowski, B. S. Rem, N. Flashner, K. Sengstock, N. Goldman, and C. Weitenberg, Measuring quantized circular dichroism in ultracold topological matter, Nat. Phys. 15, 449 (2019).
- M. Yu, P. Yang, M. Gong, Q. Cao, Q. Lu, H. Liu, S. Zhang, M. B. Plenio, F. Jelezko, T. Ozawa et al., Experimental measurement of the quantum geometric tensor using coupled qubits in diamond, Natl. Sci. Rev. 7, 254 (2020).
- X. Tan, D.-W. Zhang, Z. Yang, J. Chu, Y.-Q. Zhu, D. Li, X. Yang, S. Song, Z. Han, Z. Li, Y. Dong, H.-F. Yu, H. Yan, S.-L. Zhu, and Y. Yu, Experimental measurement of the quantum metric tensor and related topological phase transition with a superconducting qubit, Phys. Rev. Lett. 122, 210401 (2019).
- M. Yu, Y. Liu, P. Yang, M. Gong, Q. Cao, S. Zhang, H. Liu, M. Heyl, T. Ozawa, N. Goldman et al., Quantum Fisher information measurement and verification of the quantum Cramér–Rao bound in a solid-state qubit, npj Quantum Inf. 8, 56 (2022).
- M. Yu, X. Li, Y. Chu, B. Mera, F. N. Ünal, P. Yang, Y. Liu, N. Goldman, and J. Cai, Experimental demonstration of topological bounds in quantum metrology, Natl. Sci. Rev. 11, nwae065 (2024).
- M. Chen, C. Li, G. Palumbo, Y.-Q. Zhu, N. Goldman, and P. Cappellaro, A synthetic monopole source of Kalb-Ramond field in diamond, Science 375, 1017 (2022).
- X. Tan, D.-W. Zhang, W. Zheng, X. Yang, S. Song, Z. Han, Y. Dong, Z. Wang, D. Lan, H. Yan, S.-L. Zhu, and Y. Yu, Experimental observation of tensor monopoles with a superconducting qudit, Phys. Rev. Lett. 126, 017702 (2021).
- I. Souza and D. Vanderbilt, Dichroic -sum rule and the orbital magnetization of crystals, Phys. Rev. B 77, 054438 (2008).
- D. T. Tran, N. R. Cooper, and N. Goldman, Quantized Rabi oscillations and circular dichroism in quantum Hall systems, Phys. Rev. A 97, 061602(R) (2018).
- X. G. Wen, Electrodynamical properties of gapless edge excitations in the fractional quantum Hall states, Phys. Rev. Lett. 64, 2206 (1990).
- X. G. Wen, Chiral Luttinger liquid and the edge excitations in the fractional quantum Hall states, Phys. Rev. B 41, 12838 (1990).
- X.-G. Wen, Topological orders and edge excitations in fractional quantum Hall states, Adv. Phys. 44, 405 (1995).
- A. M. Chang, Chiral Luttinger liquids at the fractional quantum Hall edge, Rev. Mod. Phys. 75, 1449 (2003).
- N. Navon, R. P. Smith, and Z. Hadzibabic, Quantum gases in optical boxes, Nat. Phys. 17, 1334 (2021).
- F. Binanti, N. Goldman, and C. Repellin, Spectroscopy of edge and bulk collective modes in fractional Chern insulators, Phys. Rev. Res. 6, L012054 (2024).
- H. S. Bennett and E. A. Stern, Faraday effect in solids, Phys. Rev. 137, A448 (1965).
- R. Bianco and R. Resta, Mapping topological order in coordinate space, Phys. Rev. B 84, 241106(R) (2011).
- K. v. Klitzing, G. Dorda, and M. Pepper, New method for high-accuracy determination of the fine-structure constant based on quantized Hall resistance, Phys. Rev. Lett. 45, 494 (1980).
- R. B. Laughlin, Quantized Hall conductivity in two dimensions, Phys. Rev. B 23, 5632 (1981).
- R. B. Laughlin, Anomalous quantum Hall effect: An incompressible quantum fluid with fractionally charged excitations, Phys. Rev. Lett. 50, 1395 (1983).
- D. M. Stamper-Kurn and W. Ketterle, Spinor condensates and light scattering from Bose-Einstein condensates, in Coherent Atomic Matter Waves: 27 July–27 August 1999 (Springer, New York, 2002), pp. 139–217.
- See Supplemental Material at http://link.aps.org/supplemental/10.1103/6d6n-3trh for details. The SM includes the following additional Refs. [58–62].
- T. H. Hansson, M. Hermanns, S. H. Simon, and S. F. Viefers, Quantum Hall physics: Hierarchies and conformal field theory techniques, Rev. Mod. Phys. 89, 025005 (2017).
- N. R. Cooper, F. J. M. van Lankvelt, J. W. Reijnders, and K. Schoutens, Quantum Hall states of atomic Bose gases: Density profiles in single-layer and multilayer geometries, Phys. Rev. A 72, 063622 (2005).
- B. Oblak, B. Lapierre, P. Moosavi, J.-M. Stéphan, and B. Estienne, Anisotropic quantum Hall droplets, Phys. Rev. X 14, 011030 (2024).
- R. J. Fletcher, A. Shaffer, C. C. Wilson, P. B. Patel, Z. Yan, V. Cré pel, B. Mukherjee, and M. W. Zwierlein, Geometric squeezing into the lowest Landau level, Science 372, 1318 (2021).
- F. D. M. Haldane, Model for a quantum Hall effect without Landau levels: Condensed-matter realization of the “parity anomaly”, Phys. Rev. Lett. 61, 2015 (1988).
- A. Nardin and I. Carusotto, Linear and nonlinear edge dynamics of trapped fractional quantum Hall droplets, Phys. Rev. A 107, 033320 (2023).
- A. Nardin and I. Carusotto, Refermionized theory of the edge modes of a fractional quantum Hall cloud, Phys. Rev. A 112, 063302 (2025).
- A. S. Sørensen, E. Demler, and M. D. Lukin, Fractional quantum Hall states of atoms in optical lattices, Phys. Rev. Lett. 94, 086803 (2005).
- M. Hafezi, A. S. Sørensen, E. Demler, and M. D. Lukin, Fractional quantum Hall effect in optical lattices, Phys. Rev. A 76, 023613 (2007).
- R. N. Palmer, A. Klein, and D. Jaksch, Optical lattice quantum Hall effect, Phys. Rev. A 78, 013609 (2008).
- J. A. Kjäll and J. E. Moore, Edge excitations of bosonic fractional quantum Hall phases in optical lattices, Phys. Rev. B 85, 235137 (2012).
- G. Möller and N. R. Cooper, Composite fermion theory for bosonic quantum Hall states on lattices, Phys. Rev. Lett. 103, 105303 (2009).
- T. Scaffidi and S. H. Simon, Exact solutions of fractional Chern insulators: Interacting particles in the Hofstadter model at finite size, Phys. Rev. B 90, 115132 (2014).
- D. Bauer, T. S. Jackson, and R. Roy, Quantum geometry and stability of the fractional quantum Hall effect in the Hofstadter model, Phys. Rev. B 93, 235133 (2016).
- G. Möller and N. R. Cooper, Fractional Chern insulators in Harper-Hofstadter bands with higher Chern number, Phys. Rev. Lett. 115, 126401 (2015).
- G. Murthy, Composite fermion Hofstadter problem: Partially polarized density wave states in the fractional quantum Hall effect, Phys. Rev. Lett. 84, 350 (2000).
- M. Račiūnas, F. N. Ünal, E. Anisimovas, and A. Eckardt, Creating, probing, and manipulating fractionally charged excitations of fractional Chern insulators in optical lattices, Phys. Rev. A 98, 063621 (2018).
- C. Repellin, J. Léonard, and N. Goldman, Fractional Chern insulators of few bosons in a box: Hall plateaus from center-of-mass drifts and density profiles, Phys. Rev. A 102, 063316 (2020).
- F. A. Palm, M. Buser, J. Léonard, M. Aidelsburger, U. Schollwöck, and F. Grusdt, Bosonic pfaffian state in the Hofstadter-Bose-Hubbard model, Phys. Rev. B 103, L161101 (2021).
- J. Boesl, R. Dilip, F. Pollmann, and M. Knap, Characterizing fractional topological phases of lattice bosons near the first Mott lobe, Phys. Rev. B 105, 075135 (2022).
- W.-W. Luo, W.-C. Chen, Y.-F. Wang, and C.-D. Gong, Edge excitations in fractional Chern insulators, Phys. Rev. B 88, 161109(R) (2013).
- F. D. M. Haldane, Fractional quantization of the Hall effect: A hierarchy of incompressible quantum fluid states, Phys. Rev. Lett. 51, 605 (1983).
- B. I. Halperin, Theory of the quantized Hall conductance, Helv. Phys. Acta 56, 75 (1983).
- X. Wan, K. Yang, and E. H. Rezayi, Reconstruction of fractional quantum Hall edges, Phys. Rev. Lett. 88, 056802 (2002).
- X. Wan, E. H. Rezayi, and K. Yang, Edge reconstruction in the fractional quantum Hall regime, Phys. Rev. B 68, 125307 (2003).
- K. Yang, Field theoretical description of quantum Hall edge reconstruction, Phys. Rev. Lett. 91, 036802 (2003).
- N. Cooper, Rapidly rotating atomic gases, Adv. Phys. 57, 539 (2008).
- N. Goldman, J. Beugnon, and F. Gerbier, Detecting chiral edge states in the Hofstadter optical lattice, Phys. Rev. Lett. 108, 255303 (2012).
- N. R. Cooper and S. H. Simon, Signatures of fractional exclusion statistics in the spectroscopy of quantum Hall droplets, Phys. Rev. Lett. 114, 106802 (2015).
- E. Macaluso and I. Carusotto, Hard-wall confinement of a fractional quantum Hall liquid, Phys. Rev. A 96, 043607 (2017).
- B. Mukherjee, A. Shaffer, P. B. Patel, Z. Yan, C. C. Wilson, V. Crépel, R. J. Fletcher, and M. Zwierlein, Crystallization of bosonic quantum Hall states in a rotating quantum gas, Nature (London) 601, 58 (2022).
- P. Lunt, P. Hill, J. Reiter, P. M. Preiss, M. Gałka, and S. Jochim, Realization of a Laughlin state of two rapidly rotating fermions, Phys. Rev. Lett. 133, 253401 (2024).
- J. Léonard, S. Kim, J. Kwan, P. Segura, F. Grusdt, C. Repellin, N. Goldman, and M. Greiner, Realization of a fractional quantum Hall state with ultracold atoms, Nature (London) 619, 495 (2023).
- A. Nardin, D. De Bernardis, R. O. Umucal 𝚤lar, L. Mazza, M. Rizzi, and I. Carusotto, Quantum nonlinear optics on the edge of a few-particle fractional quantum Hall fluid in a small lattice, Phys. Rev. Lett. 133, 183401 (2024).
- Y. Zhang, G. J. Sreejith, and J. K. Jain, Creating and manipulating non-Abelian anyons in cold atom systems using auxiliary bosons, Phys. Rev. B 92, 075116 (2015).
- F. D. M. Haldane, Geometrical description of the fractional quantum Hall effect, Phys. Rev. Lett. 107, 116801 (2011).
- H. B. Xavier, Z. Bacciconi, T. Chanda, D. T. Son, and M. Dalmonte, Chiral graviton modes on the lattice, Phys. Rev. Lett. 135, 196501 (2025).