- Open Access
Thermal behavior of Bose-Einstein condensates of polar molecules
Phys. Rev. Research 7, 033080 – Published 21 July, 2025
DOI: https://doi.org/10.1103/9sbg-6qqw
Abstract
We use the finite-temperature extended Gross-Pitaevskii equation (TeGPE) to study a condensate of dipolar NaCs molecules under the conditions of the recent breakthrough experiment [Bigagli et al., Nature 631, 289 (2024)]. We report the condensate fraction of the system and its density profile after a time-of-flight expansion for the coldest experimental case, finding excellent agreement with the experimental measurements. We also report the peak density of the ground state and establish a comparison with the experimental estimates. Our results, derived from the TeGPE formalism, successfully describe the Bose-Einstein condensation of polar molecules at finite temperature.
Physics Subject Headings (PhySH)
Article Text
References (38)
- A. V. Gorshkov, P. Rabl, G. Pupillo, A. Micheli, P. Zoller, M. D. Lukin, and H. P. Büchler, Suppression of inelastic collisions between polar molecules with a repulsive shield, Phys. Rev. Lett. 101, 073201 (2008).
- J. Lin, G. Chen, M. Jin, Z. Shi, F. Deng, W. Zhang, G. Quéméner, T. Shi, S. Yi, and D. Wang, Microwave shielding of bosonic NaRb molecules, Phys. Rev. X 13, 031032 (2023).
- C. Karam, R. Vexiau, N. Bouloufa-Maafa, O. Dulieu, M. Lepers, M. M. Z. A. Borgloh, S. Ospelkaus, and L. Karpa, Two-photon optical shielding of collisions between ultracold polar molecules, Phys. Rev. Res. 5, 033074 (2023).
- N. Bigagli, C. Warner, W. Yuan, S. Zhang, I. Stevenson, T. Karman, and S. Will, Collisionally stable gas of bosonic dipolar ground-state molecules, Nat. Phys. 19, 1579 (2023).
- B. Mukherjee and J. M. Hutson, Controlling collisional loss and scattering lengths of ultracold dipolar molecules with static electric fields, Phys. Rev. Res. 6, 013145 (2024).
- N. Bigagli, W. Yuan, S. Zhang, B. Bulatovic, T. Karman, I. Stevenson, and S. Will, Observation of Bose–Einstein condensation of dipolar molecules, Nature 631, 289 (2024).
- T. Langen, J. Boronat, J. Sánchez-Baena, R. Bombín, T. Karman, and F. Mazzanti, Dipolar droplets of strongly interacting molecules, Phys. Rev. Lett. 134, 053001 (2025).
- H. Kadau, M. Schmitt, M. Wenzel, C. Wink, T. Maier, I. Ferrier-Barbut, and T. Pfau, Observing the rosensweig instability of a quantum ferrofluid, Nature 530, 194 (2016).
- M. Schmitt, M. Wenzel, F. Böttcher, I. Ferrier-Barbut, and T. Pfau, Self-bound droplets of a dilute magnetic quantum liquid, Nature 539, 259 (2016).
- I. Ferrier-Barbut, H. Kadau, M. Schmitt, M. Wenzel, and T. Pfau, Observation of quantum droplets in a strongly dipolar bose gas, Phys. Rev. Lett. 116, 215301 (2016).
- L. Chomaz, S. Baier, D. Petter, M. J. Mark, F. Wächtler, L. Santos, and F. Ferlaino, Quantum-fluctuation-driven crossover from a dilute Bose-Einstein condensate to a macrodroplet in a dipolar quantum fluid, Phys. Rev. X 6, 041039 (2016).
- F. Böttcher, M. Wenzel, J.-N. Schmidt, M. Guo, T. Langen, I. Ferrier-Barbut, T. Pfau, R. Bombín, J. Sánchez-Baena, J. Boronat, and F. Mazzanti, Dilute dipolar quantum droplets beyond the extended Gross-Pitaevskii equation, Phys. Rev. Res. 1, 033088 (2019).
- L. Tanzi, E. Lucioni, F. Famà, J. Catani, A. Fioretti, C. Gabbanini, R. N. Bisset, L. Santos, and G. Modugno, Observation of a dipolar quantum gas with metastable supersolid properties, Phys. Rev. Lett. 122, 130405 (2019).
- F. Böttcher, J.-N. Schmidt, M. Wenzel, J. Hertkorn, M. Guo, T. Langen, and T. Pfau, Transient supersolid properties in an array of dipolar quantum droplets, Phys. Rev. X 9, 011051 (2019).
- L. Chomaz, D. Petter, P. Ilzhöfer, G. Natale, A. Trautmann, C. Politi, G. Durastante, R. M. W. van Bijnen, A. Patscheider, M. Sohmen, M. J. Mark, and F. Ferlaino, Long-lived and transient supersolid behaviors in dipolar quantum gases, Phys. Rev. X 9, 021012 (2019).
- L. Tanzi, S. M. Roccuzzo, E. Lucioni, F. Famà, A. Fioretti, C. Gabbanini, G. Modugno, A. Recati, and S. Stringari, Supersolid symmetry breaking from compressional oscillations in a dipolar quantum gas, Nature 574, 382 (2019).
- M. Guo, F. Böttcher, J. Hertkorn, J.-N. Schmidt, M. Wenzel, H. P. Büchler, T. Langen, and T. Pfau, The low-energy goldstone mode in a trapped dipolar supersolid, Nature 574, 386 (2019).
- L. Tanzi, J. G. Maloberti, G. Biagioni, A. Fioretti, C. Gabbanini, and G. Modugno, Evidence of superfluidity in a dipolar supersolid from nonclassical rotational inertia, Science 371, 1162 (2021).
- M. A. Norcia, C. Politi, L. Klaus, E. Poli, M. Sohmen, M. J. Mark, R. N. Bisset, L. Santos, and F. Ferlaino, Two-dimensional supersolidity in a dipolar quantum gas, Nature 596, 357 (2021).
- G. Biagioni, Nicolò Antolini, A. Alaña, M. Modugno, A. Fioretti, C. Gabbanini, L. Tanzi, and G. Modugno, Dimensional crossover in the superfluid-supersolid quantum phase transition, Phys. Rev. X 12, 021019 (2022).
- M. Sohmen, C. Politi, L. Klaus, L. Chomaz, M. J. Mark, M. A. Norcia, and F. Ferlaino, Birth, life, and death of a dipolar supersolid, Phys. Rev. Lett. 126, 233401 (2021).
- J. Sánchez-Baena, C. Politi, F. Maucher, F. Ferlaino, and T. Pohl, Heating a dipolar quantum fluid into a solid, Nat. Commun. 14, 1868 (2023).
- J. Sánchez-Baena, T. Pohl, and F. Maucher, Superfluid-supersolid phase transition of elongated dipolar Bose-Einstein condensates at finite temperatures, Phys. Rev. Res. 6, 023183 (2024).
- L.-J. He, J. Sánchez-Baena, F. Maucher, and Y.-C. Zhang, Accessing elusive two-dimensional phases of dipolar Bose-Einstein condensates by finite temperature, Phys. Rev. Res. 7, 023019 (2025).
- M. Lu, N. Q. Burdick, S. H. Youn, and B. L. Lev, Strongly dipolar Bose-Einstein condensate of dysprosium, Phys. Rev. Lett. 107, 190401 (2011).
- K. Aikawa, A. Frisch, M. Mark, S. Baier, A. Rietzler, R. Grimm, and F. Ferlaino, Bose-Einstein condensation of erbium, Phys. Rev. Lett. 108, 210401 (2012).
- S. Giorgini, L. P. Pitaevskii, and S. Stringari, Thermodynamics of a trapped Bose-condensed gas, J. Low Temp. Phys. 109, 309 (1997).
- A. Boudjemâa, Quantum dilute droplets of dipolar bosons at finite temperature, Ann. Phys. 381, 68 (2017).
- A. Boudjemâa, Fluctuations and quantum self-bound droplets in a dipolar Bose-Bose mixture, Phys. Rev. A 98, 033612 (2018).
- E. Aybar and M. Ö. Oktel, Temperature-dependent density profiles of dipolar droplets, Phys. Rev. A 99, 013620 (2019).
- S. F. Öztürk, E. Aybar, and M. Ö. Oktel, Temperature dependence of the density and excitations of dipolar droplets, Phys. Rev. A 102, 033329 (2020).
- A. R. P. Lima and A. Pelster, Quantum fluctuations in dipolar Bose gases, Phys. Rev. A 84, 041604 (2011).
- A. R. P. Lima and A. Pelster, Beyond mean-field low-lying excitations of dipolar Bose gases, Phys. Rev. A 86, 063609 (2012).
- F. Dalfovo, S. Giorgini, L. P. Pitaevskii, and S. Stringari, Theory of Bose-Einstein condensation in trapped gases, Rev. Mod. Phys. 71, 463 (1999).
- T. Karman, N. Bigagli, W. Yuan, S. Zhang, I. Stevenson, and S. Will, Double microwave shielding, PRX Quantum 6, 020358 (2025).
- F. Deng, X. Hu, W.-J. Jin, S. Yi, and T. Shi, Two- and many-body physics of ultracold molecules dressed by dual microwave fields, arXiv:2501.05210.
- A. Boudjemâa, Nonequilibrium quench dynamics of Bose-Einstein condensates of microwave-shielded polar molecules, Phys. Rev. A 111, 063315 (2025).
- S. Yi and L. You, Trapped condensates of atoms with dipole interactions, Phys. Rev. A 63, 053607 (2001).