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Optical control of a metastable phase in the charge density wave Mott insulator 1T−TaS2 investigated using time- and angle-resolved photoemission spectroscopy

Tanusree Saha1,2,*, Arindam Pramanik3,4, Rokaya Osama2, Fabio Frassetto5, Damjan Krizmancic6, Luca Poletto5, Arun Ravindran2, Barbara Ressel2, Primož Rebernik Ribič7 et al.

Giovanni De Ninno2,7

  • *Contact author: tanusree.saha@uni-due.de
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Phys. Rev. B 113, 035113 – Published 6 January, 2026

DOI: https://doi.org/10.1103/gz2s-685y

Abstract

Light-induced metastable phases are exotic, long-lived out-of-equilibrium states of matter. Optical control offers a powerful approach to engineering these phases, enabling dynamic tuning of their electronic and structural properties. Using time- and angle-resolved photoemission spectroscopy, we investigate the emergence of a metastable phase induced by a strong infrared pump in the charge-density-wave (CDW)-Mott insulator 1T−TaS2. Furthermore, we demonstrate how its properties can be optically manipulated by varying the photoexcitation strength. A long-lived stabilization of the renormalized electronic band structure serves as a signature of the metastable phase. It displays a relaxed periodic lattice distortion (PLD) and primarily lattice-driven dynamics. The emergence of a new dispersive band in the vicinity of the Hubbard bands reveals the formation of a novel band structure unique to the metastable phase. Our pump-fluence-dependent studies reveal a threshold (incident) fluence FC∼1.3mJ/cm2 for inducing the metastable phase, above which the band renormalization continuously evolves with increasing fluence. For F⩽ 3.4 mJ/cm2, stronger photoexcitation progressively drives the phase to higher energies, accompanied by a more relaxed PLD and reduced CDW amplitude. The properties of the metastable phase are strongly influenced by the transient dynamics at each fluence, and the associated fast timescales suggest that the intrinsic CDW amplitude mode remains unaffected by optical manipulation. These findings highlight the potential of optical control in tuning the properties of metastable phases in quantum materials, offering new insights into the manipulation of CDW systems and paving the way for future investigations in nonequilibrium phase engineering.

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Corrections

13 February, 2026

Correction: The omission of a support statement in the Acknowledgments has been fixed.

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References (66)

  1. J. Zhang and R. D. Averitt, Dynamics and control in complex transition metal oxides, Annu. Rev. Mater. Res. 44, 19 (2014).
  2. D. N. Basov, R. D. Averitt, and D. Hsieh, Towards properties on demand in quantum materials, Nat. Mater. 16, 1077 (2017).
  3. M. Mitrano, A. Cantaluppi, D. Nicoletti, S. Kaiser, A. Perucchi, S. Lupi, P. Di Pietro, D. Pontiroli, M. Riccò, S. R. Clark, and A. Cavalleri, Possible light-induced superconductivity in K3C60 at high temperature, Nature (London) 530, 461 (2016).
  4. D. Fausti, R. I. Tobey, N. Dean, S. Kaiser, A. Dienst, M. C. Hoffmann, S. Pyon, T. Takayama, H. Takagi, and A. Cavalleri, Light-induced superconductivity in a stripe-ordered cuprate, Science 331, 189 (2011).
  5. K. A. Cremin, J. Zhang, C. C. Homes, G. D. Gu, Z. Sun, M. M. Fogler, A. J. Millis, D. N. Basov, and R. D. Averitt, Photoenhanced metastable c-axis electrodynamics in stripe-ordered cuprate La1.885Ba0.115CuO4, Proc. Natl. Acad. Sci. USA 116, 19875 (2019).
  6. M. Först, C. Manzoni, S. Kaiser, Y. Tomioka, Y. Tokura, R. Merlin, and A. Cavalleri, Nonlinear phononics as an ultrafast route to lattice control, Nat. Phys. 7, 854 (2011).
  7. T. F. Nova, A. Cartella, A. Cantaluppi, M. Forst, D. Bossini, R. V. Mikhaylovskiy, A. V. Kimel, R. Merlin, and A. Cavalleri, An effective magnetic field from optically driven phonons, Nat. Phys. 13, 132 (2017).
  8. X. Li, T. Qiu, J. Zhang, E. Baldini, J. Lu, A. M. Rappe, and K. A. Nelson, Terahertz field-induced ferroelectricity in quantum paraelectric SrTiO3, Science 364, 1079 (2019).
  9. Y. H. Wang, H. Steinberg, P. Jarillo-Herrero, and N. Gedik, Observation of Floquet-Bloch states on the surface of a topological insulator, Science 342, 453 (2013).
  10. F. Mahmood, C.-K. Chan, Z. Alpichshev, D. Gardner, Y. Lee, P. A. Lee, and N. Gedik, Selective scattering between Floquet-Bloch and Volkov states in a topological insulator, Nat. Phys. 12, 306 (2016).
  11. A. de la Torre, D. M. Kennes, M. Claassen, S. Gerber, J. W. McIver, and M. A. Sentef, Nonthermal pathways to ultrafast control in quantum materials, Rev. Mod. Phys. 93, 041002 (2021).
  12. C. L. Smallwood, J. P. Hinton, C. Jozwiak, W. Zhang, J. D. Koralek, H. Eisaki, D.-H. Lee, J. Orenstein, and A. Lanzara, Tracking Cooper pairs in a cuprate superconductor by ultrafast angle-resolved photoemission, Science 336, 1137 (2012).
  13. J. G. Horstmann, H. Böckmann, B. Wit, F. Kurtz, G. Storeck, and C. Ropers, Coherent control of a surface structural phase transition, Nature (London) 583, 232 (2020).
  14. K. M. Siddiqui, D. B. Durham, F. Cropp, C. Ophus, S. Rajpurohit, Y. Zhu, J. D. Carlström, C. Stavrakas, Z. Mao, A. Raja, P. Musumeci, L. Z. Tan, A. M. Minor, D. Filippetto, and R. A. Kaindl, Ultrafast optical melting of trimer superstructure in layered 1T'-TaTe2, Commun. Phys. 4, 152 (2021).
  15. M. Tuniz, D. Soranzio, D. Bidoggia, D. Puntel, W. Bronsch, S. L. Johnson, M. Peressi, F. Parmigiani, and F. Cilento, Ultrafast all-optical manipulation of the charge-density wave in VTe2, Phys. Rev. Res. 5, 043276 (2023).
  16. T. Domröse, T. Danz, S. F. Schaible, K. Rossnagel, S. V. Yalunin, and C. Ropers, Light-induced hexatic state in a layered quantum material, Nat. Mater. 22, 1345 (2023).
  17. H. Mittenzwey, A. M. Kumar, R. Dhingra, K. Watanabe, T. Taniguchi, C. Gahl, K. I. Bolotin, M. Selig, and A. Knorr, Ultrafast optical control of Rashba interactions in a TMDC heterostructure, Phys. Rev. Lett. 134, 026901 (2025).
  18. V. R. Morrison, R. P. Chatelain, K. L. Tiwari, A. Hendaoui, A. Bruhács, M. Chaker, and B. J. Siwick, A photoinduced metal-like phase of monoclinic VO2 revealed by ultrafast electron diffraction, Science 346, 445 (2014).
  19. M. R. Otto, L. P. R. de Cotret, D. A. Valverde-Chavez, K. L. Tiwari, N. Émond, M. Chaker, D. G. Cooke, and B. J. Siwick, How optical excitation controls the structure and properties of vanadium dioxide, Proc. Natl. Acad. Sci. USA 116, 450 (2019).
  20. X. Shi, W. You, Y. Zhang, Z. Tao, P. M. Oppeneer, X. Wu, R. Thomale, K. Rossnagel, M. Bauer, H. Kapteyn, and M. Murnane, Ultrafast electron calorimetry uncovers a new long-lived metastable state in 1T−TaSe2 mediated by mode-selective electron-phonon coupling, Sci. Adv. 5, eaav4449 (2019).
  21. J. Zhang, X. Tan, M. Liu, S. W. Teitelbaum, K. W. Post, F. Jin, K. A. Nelson, D. N. Basov, W. Wu, and R. D. Averitt, Cooperative photoinduced metastable phase control in strained manganite films, Nat. Mater. 15, 956 (2016).
  22. L. Stojchevska, I. Vaskivskyi, T. Mertelj, P. Kusar, D. Svetin, S. Brazovskii, and D. Mihailovic, Ultrafast switching to a stable hidden quantum state in an electronic crystal, Science 344, 177 (2014).
  23. A. S. McLeod, J. Zhang, M. Q. Gu, F. Jin, G. Zhang, K. W. Post, X. G. Zhao, A. J. Millis, W. B. Wu, J. M. Rondinelli, R. D. Averitt, and D. N. Basov, Multi-messenger nanoprobes of hidden magnetism in a strained manganite, Nat. Mater. 19, 397 (2020).
  24. Q. M. Liu, D. Wu, Z. A. Li, L. Y. Shi, Z. X. Wang, S. J. Zhang, T. Lin, T. C. Hu, H. F. Tian, J. Q. Li, T. Dong, and N. L. Wang, Photoinduced multistage phase transitions in Ta2NiSe5, Nat. Commun. 12, 2050 (2021).
  25. D. Mihailovic, D. Svetin, I. Vaskivskyi, R. Venturini, B. Lipovšek, and A. Mraz, Ultrafast non-thermal and thermal switching in charge configuration memory devices based on 1T−TaS2, Appl. Phys. Lett. 119, 013106 (2021).
  26. A. Milloch, M. Fabrizio, and C. Giannetti, Mott materials: Unsuccessful metals with a bright future, npj Spintronics 2, 49 (2024).
  27. M. Budden, T. Gebert, M. Buzzi, G. Jotzu, E. Wang, T. Matsuyama, G. Meier, Y. Laplace, D. Pontiroli, M. Riccò, F. Schlawin, D. Jaksch, and A. Cavalleri, Evidence for metastable photo-induced superconductivity in K3C60, Nat. Phys. 17, 611 (2021).
  28. I. Vaskivskyi, J. Gospodaric, S. Brazovskii, D. Svetin, P. Sutar, E. Goreshnik, I. A. Mihailovic, T. Mertelj, and D. Mihailovic, Controlling the metal-to-insulator relaxation of the metastable hidden quantum state in 1T−TaS2, Sci. Adv. 1, e1500168 (2015).
  29. I. Vaskivskyi, I. A. Mihailovic, S. Brazovskii, J. Gospodaric, T. Mertelj, D. Svetin, P. Sutar, and D. Mihailovic, Fast electronic resistance switching involving hidden charge density wave states, Nat. Commun. 7, 11442 (2016).
  30. J. Ravnik, M. Diego, Y. Gerasimenko, Y. Vaskivskyi, I. Vaskivskyi, T. Mertelj, J. Vodeb, and D. Mihailovic, A time-domain phase diagram of metastable states in a charge ordered quantum material, Nat. Commun. 12, 2323 (2021).
  31. Y. A. Gerasimenko, P. Karpov, I. Vaskivskyi, S. Brazovskii, and D. Mihailovic, Intertwined chiral charge orders and topological stabilization of the light-induced state of a prototypical transition metal dichalcogenide, npj Quantum Mater. 4, 32 (2019).
  32. K. Sun, S. Sun, C. Zhu, H. Tian, H. Yang, and J. Li, Hidden CDW states and insulator-to-metal transition after a pulsed femtosecond laser excitation in layered chalcogenide 1T−TaS1−xSex, Sci. Adv. 4, eaas9660 (2018).
  33. Q. Stahl, M. Kusch, F. Heinsch, G. Garbarino, N. Kretzschmar, K. Hanff, K. Rossnagel, J. Geck, and T. Ritschel, Collapse of layer dimerization in the photo-induced hidden state of 1T−TaS2, Nat. Commun. 11, 1247 (2020).
  34. L. Ma, C. Ye, Y. Yu, X. F. Lu, X. Niu, S. Kim, D. Feng, D. Tománek, Y.-W. Son, X. H. Chen, and Y. Zhang, A metallic mosaic phase and the origin of Mott-insulating state in 1T−TaS2, Nat. Commun. 7, 10956 (2016).
  35. D. Cho, S. Cheon, K.-S. Kim, S.-H. Lee, Y.-H. Cho, S.-W. Cheong, and H. W. Yeom, Nanoscale manipulation of the Mott insulating state coupled to charge order in 1T−TaS2, Nat. Commun. 7, 10453 (2016).
  36. J. Ravnik, I. Vaskivskyi, T. Mertelj, and D. Mihailovic, Real-time observation of the coherent transition to a metastable emergent state in 1T−TaS2, Phys. Rev. B 97, 075304 (2018).
  37. F. Y. Gao, Z. Zhang, Z. Sun, L. Ye, Y.-H. Cheng, Z.-J. Liu, J. G. Checkelsky, E. Baldini, and K. A. Nelson, Snapshots of a light-induced metastable hidden phase driven by the collapse of charge order, Sci. Adv. 8, eabp9076 (2022).
  38. J. Maklar, J. Sarkar, S. Dong, Y. A. Gerasimenko, T. Pincelli, S. Beaulieu, P. S. Kirchmann, J. A. Sobota, S. Yang, D. Leuenberger, R. G. Moore, Z.-X. Shen, M. Wolf, D. Mihailovic, R. Ernstorfer, and L. Rettig, Coherent light control of a metastable hidden state, Sci. Adv. 9, eadi4661 (2023).
  39. C. J. Butler, M. Yoshida, T. Hanaguri, and Y. Iwasa, Mottness versus unit-cell doubling as the driver of the insulating state in 1T−TaS2, Nat. Commun. 11, 2477 (2020).
  40. C. B. Scruby, P. M. Williams, and G. S. Parry, The role of charge density waves in structural transformations of 1T−TaS2, Philos. Mag. 31, 255 (1975).
  41. R. H. Friend and A. D. Yoffe, Electronic properties of intercalation complexes of the transition-metal dichalcogenides, Adv. Phys. 36, 1 (1987).
  42. J. A. Wilson, F. J. D. Salvo, and S. Mahajan, Charge-density waves and superlattices in the metallic layered transition-metal dichalcogenides, Adv. Phys. 24, 117 (1975).
  43. N. V. Smith, S. D. Kevan, and F. J. D. Salvo, Band structures of the layer compounds 1T−TaS2 and 2H−TaSe2 in the presence of commensurate charge-density waves, J. Phys. C 18, 3175 (1985).
  44. K. Rossnagel and N. V. Smith, Spin-orbit coupling in the band structure of reconstructed 1T−TaS2, Phys. Rev. B 73, 073106 (2006).
  45. Y. D. Wang, W. L. Yao, Z. M. Xin, T. T. Han, Z. G. Wang, L. Chen, C. Cai, Y. Li, and Y. Zhang, Band insulator to Mott insulator transition in 1T−TaS2, Nat. Commun. 11, 4215 (2020).
  46. P. Fazekas and E. Tosatti, Electrical, structural and magnetic properties of pure and doped 1T−TaS2, Philos. Mag. B 39, 229 (1979).
  47. W. Wang, D. Dietzel, and A. Schirmeisen, Lattice discontinuities of 1T−TaS2 across first order charge density wave phase transitions, Sci. Rep. 9, 7066 (2019).
  48. T. Ritschel, J. Trinckauf, K. Koepernik, B. Buüchner, M. V. Zimmermann, H. Berger, Y. I. Joe, P. Abbamonte, and J. Geck, Orbital textures and charge density waves in transition metal dichalcogenides, Nat. Phys. 11, 328 (2015).
  49. S.-H. Lee, J. S. Goh, and D. Cho, Origin of the insulating phase and first-order metal-insulator transition in 1T−TaS2, Phys. Rev. Lett. 122, 106404 (2019).
  50. C. W. Nicholson, F. Petocchi, B. Salzmann, C. Witteveen, M. Rumo, G. Kremer, F. O. von Rohr, P. Werner, and C. Monney, Gap collapse and flat band induced by uniaxial strain in 1T−TaS2, Phys. Rev. B 109, 035167 (2024).
  51. L. Perfetti, P. A. Loukakos, M. Lisowski, U. Bovensiepen, M. Wolf, H. Berger, S. Biermann, P. S. Cornaglia, A. Georges, and M. Wolf, Time evolution of the electronic structure of 1T−TaS2 through the insulator-metal transition, Phys. Rev. Lett. 97, 067402 (2006).
  52. L. Perfetti, P. A. Loukakos, M. Lisowski, U. Bovensiepen, M. Wolf, H. Berger, S. Biermann, and A. Georges, Femtosecond dynamics of electronic states in the Mott insulator 1T−TaS2 by time-resolved photoelectron spectroscopy, New J. Phys. 10, 053019 (2008).
  53. S. Hellmann, T. Rohwer, M. Kalläne, K. Hanff, C. Sohrt, A. Stange, A. Carr, M. M. Murnane, H. C. Kapteyn, L. Kipp, M. Bauer, and K. Rossnagel, Time-domain classification of charge-density-wave insulators, Nat. Commun. 3, 1069 (2012).
  54. J. C. Petersen, S. Kaiser, N. Dean, A. Simoncig, H. Y. Liu, A. L. Cavalieri, C. Cacho, I. C. E. Turcu, E. Springate, F. Frassetto, L. Poletto, S. S. Dhesi, H. Berger, and A. Cavalleri, Clocking the melting transition of charge and lattice order in 1T−TaS2 with ultrafast extreme-ultraviolet angle-resolved photoemission spectroscopy, Phys. Rev. Lett. 107, 177402 (2011).
  55. C. Sohrt, A. Stange, M. Bauer, and K. Rossnagel, How fast can a Peierls–Mott insulator be melted? Faraday Discuss. 171, 243 (2014).
  56. M. Ligges, I. Avigo, D. Golež, H. U. R. Strand, Y. Beyazit, K. Hanff, F. Diekmann, L. Stojchevska, M. Kalläne, P. Zhou, K. Rossnagel, M. Eckstein, P. Werner, and U. Bovensiepen, Ultrafast doublon dynamics in photoexcited 1T−TaS2, Phys. Rev. Lett. 120, 166401 (2018).
  57. T. Saha, A. Pramanik, B. Ressel, A. Ciavardini, F. Frassetto, F. Galdenzi, L. Poletto, A. Ravindran, P. R. Ribič, and G. D. Ninno, Uncovering the nature of transient and metastable nonequilibrium phases in 1T−TaS2, Phys. Rev. B 108, 035157 (2023).
  58. S. Hellmann, M. Beye, C. Sohrt, T. Rohwer, F. Sorgenfrei, H. Redlin, M. Kalläne, M. Marczynski-Bühlow, F. Hennies, M. Bauer, A. Föhlisch, L. Kipp, W. Wurth, and K. Rossnagel, Time-domain classification of charge-density-wave insulators, Phys. Rev. Lett. 105, 187401 (2010).
  59. M. Eichberger, H. Schäfer, M. Krumova, M. Beyer, J. Demsar, H. Berger, G. Moriena, G. Sciaini, and R. J. Dwayne Miller, Snapshots of cooperative atomic motions in the optical suppression of charge density waves, Nature (London) 468, 799 (2010).
  60. C. Bao, H. Zhong, F. Wang, T. Lin, H. Zhang, Z. Sun, W. Duan, and S. Zhou, Distinguishing and controlling Mottness in 1T−TaS2 by ultrafast light, Phys. Rev. B 107, L121103 (2023).
  61. C. Grazioli, C. Callegari, A. Ciavardini, M. Coreno, F. Frassetto, D. Gauthier, D. Golob, R. Ivanov, A. Kivimäki, B. Mahieu, B. Bučar, M. Merhar, P. Miotti, L. Poletto, E. Polo, B. Ressel, C. Spezzani, and G. De Ninno, CITIUS: An infrared-extreme ultraviolet light source for fundamental and applied ultrafast science, Rev. Sci. Instrum. 85, 023104 (2014).
  62. L. Poletto, P. Villoresi, F. Frassetto, F. Calegari, F. Ferrari, M. Lucchini, G. Sansone, and M. Nisoli, Time-delay compensated monochromator for the spectral selection of extreme-ultraviolet high-order laser harmonics, Rev. Sci. Instrum. 80, 123109 (2009).
  63. J. R. Duffey, R. D. Kirby, and R. V. Coleman, Raman scattering from 1T−TaS2, Solid State Commun. 20, 617 (1976).
  64. J. Demsar, L. Forró, H. Berger, and D. Mihailovic, Femtosecond snapshots of gap-forming charge-density-wave correlations in quasi-two-dimensional dichalcogenides 1T−TaS2 and 2H−TaSe2, Phys. Rev. B 66, 041101(R) (2002).
  65. See Supplemental Material at http://link.aps.org/supplemental/10.1103/gz2s-685y for momentum-resolved EDC stacks along K¯←M¯→K¯ at different temperatures, clearly showing that the bandwidth narrows as the temperature increases.
  66. A. Damascelli, Probing the low-energy electronic structure of complex systems by ARPES, Phys. Scr. T109, 61 (2004).

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Phys. Rev. B 113, 035113– Published 6 January, 2026
  • Received 29 May 2025
  • Revised 20 October 2025
  • Accepted 19 November 2025
  • Corrected 13 February 2026
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