Blatt, J. M., Böer, K. W. & Brandt, W. Bose-Einstein condensation of excitons. Phys. Rev. 126, 1691–1692 (1962).
Google Scholar
Lozovik, Y. E. & Yudson, V. I. Feasibility of superfluidity of paired spatially separated electrons and holes; a new superconductivity mechanism. JETP Lett. 22, 274–276 (1975).
Google Scholar
Li, J. I. A. et al. Pairing states of composite fermions in double-layer graphene. Nat. Phys. 15, 898–903 (2019).
Google Scholar
Liu, X. et al. Interlayer fractional quantum Hall effect in a coupled graphene double layer. Nat. Phys. 15, 893–897 (2019).
Google Scholar
Laughlin, R. Excitons in the fractional quantum Hall effect. Physica B+C 126, 254–259 (1984).
Google Scholar
Wen, X.-G. & Zee, A. Neutral superfluid modes and “magnetic” monopoles in multilayered quantum Hall systems. Phys. Rev. Lett. 69, 1811–1814 (1992).
Google Scholar
Kamilla, R. K. & Jain, J. K. Excitonic instability and termination of fractional quantum Hall effect. Phys. Rev. B 55, R13417–R13420 (1997).
Google Scholar
Yang, J. Quasiexcitons in the fractional quantum Hall effect. Phys. Rev. B 49, 5443–5447 (1994).
Google Scholar
Park, K. & Jain, J. K. Two-roton bound state in the fractional quantum Hall effect. Phys. Rev. Lett. 84, 5576–5579 (2000).
Google Scholar
Park, K. Charged excitons of composite fermions in the fractional quantum Hall effect. Solid State Commun. 121, 19–23 (2001).
Google Scholar
Jain, J. K., Park, K., Peterson, M. R. & Scarola, V. W. Composite fermion theory of excitations in the fractional quantum Hall effect. Solid State Commun. 135, 602–609 (2005).
Google Scholar
Quinn, J. J., Wójs, A. & Gładysiewicz, A. Fractional quasiexcitons in incompressible electron liquids. Physica E 34, 280–283 (2006).
Google Scholar
Barkeshli, M., Nayak, C., Papić, Z., Young, A. & Zaletel, M. Topological exciton Fermi surfaces in two-component fractional quantized Hall insulators. Phys. Rev. Lett. 121, 026603 (2018).
Google Scholar
Zhang, Y.-H., Zhu, Z. & Vishwanath, A. XY* transition and extraordinary boundary criticality from fractional exciton condensation in quantum Hall bilayer. Phys. Rev. X 13, 031023 (2023).
Google Scholar
Kwan, Y. H., Hu, Y., Simon, S. H. & Parameswaran, S. A. Excitonic fractional quantum Hall hierarchy in moiré heterostructures. Phys. Rev. B 105, 235121 (2022).
Google Scholar
Faugno, W. N., Balram, A. C., Wójs, A. & Jain, J. K. Theoretical phase diagram of two-component composite fermions in double-layer graphene. Phys. Rev. B 101, 085412 (2020).
Google Scholar
Feldman, D. E. & Halperin, B. I. Fractional charge and fractional statistics in the quantum Hall effects. Rep. Prog. Phys. 84, 076501 (2021).
Google Scholar
Halperin, B. I. Theory of the quantized Hall conductance. Helv. Phys. Acta 56, 75–102 (1983).
Google Scholar
Yang, K. et al. Quantum ferromagnetism and phase transitions in double-layer quantum Hall systems. Phys. Rev. Lett. 72, 732–735 (1994).
Google Scholar
Moon, K. et al. Spontaneous interlayer coherence in double-layer quantum Hall systems: Charged vortices and Kosterlitz-Thouless phase transitions. Phys. Rev. B 51, 5138–5170 (1995).
Google Scholar
Girvin, S. & MacDonald, A. Perspectives in Quantum Hall Effects: Novel Quantum Liquids in Low-Dimensional Semiconductor Structures (eds Sarma, S. D. & Pinczuk, A.) 161–224 (Wiley, 1996).
Eisenstein, J. P. Exciton condensation in bilayer quantum Hall systems. Annu. Rev. Condens. Matter Phys. 5, 159–181 (2014).
Google Scholar
Li, J. I. A., Taniguchi, T., Watanabe, K., Hone, J. & Dean, C. R. Excitonic superfluid phase in double bilayer graphene. Nat. Phys. 13, 751–755 (2017).
Google Scholar
Liu, X., Taniguchi, T., Watanabe, K., Halperin, B. & Kim, P. Quantum Hall drag of exciton condensate in graphene. Nat. Phys. 13, 746–750 (2017).
Google Scholar
Liu, X. et al. Crossover between strongly coupled and weakly coupled exciton superfluids. Science 375, 205–209 (2022).
Google Scholar
Jain, J. K. Composite Fermions (Cambridge Univ. Press, 2003).
Nandi, D., Finck, A. D. K., Eisenstein, J. P., Pfeiffer, L. N. & West, K. W. Exciton condensation and perfect coulomb drag. Nature 488, 481–484 (2012).
Google Scholar
Zeng, Y. et al. High-quality magnetotransport in graphene using the edge-free Corbino geometry. Phys. Rev. Lett. 122, 137701 (2019).
Google Scholar
Polshyn, H. et al. Quantitative transport measurements of fractional quantum Hall energy gaps in edgeless graphene devices. Phys. Rev. Lett. 121, 226801 (2018).
Google Scholar
Kellogg, M., Eisenstein, J. P., Pfeiffer, L. N. & West, K. W. Vanishing Hall resistance at high magnetic field in a double-layer two-dimensional electron system. Phys. Rev. Lett. 93, 036801 (2004).
Google Scholar
Tutuc, E., Shayegan, M. & Huse, D. A. Counterflow measurements in strongly correlated GaAs hole bilayers: evidence for electron-hole pairing. Phys. Rev. Lett. 93, 036802 (2004).
Google Scholar
Zeng, Y. et al. Evidence for a superfluid-to-solid transition of bilayer excitons. Preprint at arxiv.org/abs/2306.16995 (2023).
Jain, J. K. Composite fermion theory of exotic fractional quantum Hall effect. Annu. Rev. Condens. Matter Phys. 6, 39–62 (2015).
Google Scholar
Eisenstein, J. & Stormer, H. The fractional quantum Hall effect. Science 248, 1510–1516 (1990).
Google Scholar
Scarola, V. W. & Jain, J. K. Phase diagram of bilayer composite fermion states. Phys. Rev. B 64, 085313 (2001).
Google Scholar
Huse, D. A. Resistance due to vortex motion in the ν = 1 bilayer quantum Hall superfluid. Phys. Rev. B 72, 064514 (2005).
Google Scholar
Kellogg, M. J. Evidence for Excitonic Superfluidity in a Bilayer Two-Dimensional Electron System. PhD thesis (California Institute of Technology, 2005).
Kosterlitz, J. M. & Thouless, D. J. Ordering, metastability and phase transitions in two-dimensional systems. J. Phys. C: Solid State Phys. 6, 1181–1203 (1973).
Google Scholar
Berezinskiĭ, V. L. Destruction of long-range order in one-dimensional and two-dimensional systems possessing a continuous symmetry group. II. Quantum systems. Sov. Phys. JETP 34, 610–616 (1972).
Google Scholar
Wen, X.-G.Quantum Field Theory of Many-Body Systems: From the Origin of Sound to an Origin of Light and Electrons (Oxford Univ. Press, 2004).
Heiblum, M. & Feldman, D. E. Edge probes of topological order. Int. J. Mod. Phys. A 35, 2030009 (2020).
Google Scholar
Bid, A. et al. Observation of neutral modes in the fractional quantum Hall regime. Nature 466, 585–590 (2010).
Google Scholar
Takei, S., Halperin, B. I., Yacoby, A. & Tserkovnyak, Y. Superfluid spin transport through antiferromagnetic insulators. Phys. Rev. B 90, 094408 (2014).
Google Scholar
Takei, S., Yacoby, A., Halperin, B. I. & Tserkovnyak, Y. Spin Superfluidity in the ν = 0 quantum Hall state of graphene. Phys. Rev. Lett. 116, 216801 (2016).
Google Scholar
Wei, D. S. et al. Electrical generation and detection of spin waves in a quantum Hall ferromagnet. Science 362, 229–233 (2018).
Google Scholar
Zhou, H. et al. Strong-magnetic-field magnon transport in monolayer graphene. Phys. Rev. X 12, 021060 (2022).
Google Scholar
Eisenstein, J. P., Stormer, H. L., Pfeiffer, L. & West, K. W. Evidence for a phase transition in the fractional quantum Hall effect. Phys. Rev. Lett. 62, 1540–1543 (1989).
Google Scholar
Eisenstein, J. P., Stormer, H. L., Pfeiffer, L. N. & West, K. W. Evidence for a spin transition in the ν = 2/3 fractional quantum Hall effect. Phys. Rev. B 41, 7910 (1990).
Google Scholar
Engel, L. W., Hwang, S. W., Sajoto, T., Tsui, D. C. & Shayegan, M. Fractional quantum Hall effect at ν = 2/3 and 3/5 in tilted magnetic fields. Phys. Rev. B 45, 3418–3425 (1992).
Google Scholar
