symmetry broken supersolid in spin–orbit-coupled Bose–Einstein condensates
Supersolid is an exotic state of matter characterized by both superfluid properties and periodic particle density modulation, due to spontaneous breaking of U (1) gauge symmetry and spatial translation symmetry, respectively. For conventional supersolids, continuous translation symmetry breaking is...
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IOP Publishing
2024-01-01
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| Series: | New Journal of Physics |
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| Online Access: | https://doi.org/10.1088/1367-2630/ad98b5 |
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| author | Ze-Hong Guo Qizhong Zhu |
| author_facet | Ze-Hong Guo Qizhong Zhu |
| author_sort | Ze-Hong Guo |
| collection | DOAJ |
| description | Supersolid is an exotic state of matter characterized by both superfluid properties and periodic particle density modulation, due to spontaneous breaking of U (1) gauge symmetry and spatial translation symmetry, respectively. For conventional supersolids, continuous translation symmetry breaking is accompanied by one gapless Goldstone mode in the excitation spectra. An interesting question naturally arises: what is the consequence of breaking discrete translation symmetry for supersolids? In this work, we study the consequence of discrete symmetry breaking in a $\mathbb{Z}_n$ supersolid resulting from spontaneous breaking of a discrete $\mathbb{Z}_n$ symmetry, or equivalently, a discrete translation symmetry. This $\mathbb{Z}_n$ supersolid is realized in the stripe phase of spin–orbit-coupled Bose–Einstein condensate under an external periodic potential with period $1/n$ of intrinsic stripe period. For $n\unicode{x2A7E}2$ , there are n degenerate ground states with spontaneously broken lattice translation symmetry. The low-energy excitations of $\mathbb{Z}_n$ supersolid include a pseudo-Goldstone mode, whose excitation gap at long wavelength limit is found to decrease rapidly with n . We further numerically show that, when confined in a harmonic trap, a spin-dependent perturbation can result in the transition between degenerate ground states of $\mathbb{Z}_n$ supersolid. With the integer n tunable using the experimental technique of generating subwavelength optical lattice, the $\mathbb{Z}_n$ supersolid proposed here offers a cold atom platform to simulate physics related with generic $\mathbb{Z}_n$ symmetry breaking in a highly controllable setting. |
| format | Article |
| id | doaj-art-47ec1d8bf5364348895bb09d3d1d9e85 |
| institution | Kabale University |
| issn | 1367-2630 |
| language | English |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
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| series | New Journal of Physics |
| spelling | doaj-art-47ec1d8bf5364348895bb09d3d1d9e852024-12-10T10:19:35ZengIOP PublishingNew Journal of Physics1367-26302024-01-01261212300910.1088/1367-2630/ad98b5symmetry broken supersolid in spin–orbit-coupled Bose–Einstein condensatesZe-Hong Guo0Qizhong Zhu1https://orcid.org/0000-0002-9798-9075Key Laboratory of Atomic and Subatomic Structure and Quantum Control (Ministry of Education), Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matter, School of Physics, South China Normal University , Guangzhou 510006, People’s Republic of China; Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, Guangdong-Hong Kong Joint Laboratory of Quantum Matter, Frontier Research Institute for Physics, South China Normal University , Guangzhou 510006, People’s Republic of ChinaKey Laboratory of Atomic and Subatomic Structure and Quantum Control (Ministry of Education), Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matter, School of Physics, South China Normal University , Guangzhou 510006, People’s Republic of China; Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, Guangdong-Hong Kong Joint Laboratory of Quantum Matter, Frontier Research Institute for Physics, South China Normal University , Guangzhou 510006, People’s Republic of ChinaSupersolid is an exotic state of matter characterized by both superfluid properties and periodic particle density modulation, due to spontaneous breaking of U (1) gauge symmetry and spatial translation symmetry, respectively. For conventional supersolids, continuous translation symmetry breaking is accompanied by one gapless Goldstone mode in the excitation spectra. An interesting question naturally arises: what is the consequence of breaking discrete translation symmetry for supersolids? In this work, we study the consequence of discrete symmetry breaking in a $\mathbb{Z}_n$ supersolid resulting from spontaneous breaking of a discrete $\mathbb{Z}_n$ symmetry, or equivalently, a discrete translation symmetry. This $\mathbb{Z}_n$ supersolid is realized in the stripe phase of spin–orbit-coupled Bose–Einstein condensate under an external periodic potential with period $1/n$ of intrinsic stripe period. For $n\unicode{x2A7E}2$ , there are n degenerate ground states with spontaneously broken lattice translation symmetry. The low-energy excitations of $\mathbb{Z}_n$ supersolid include a pseudo-Goldstone mode, whose excitation gap at long wavelength limit is found to decrease rapidly with n . We further numerically show that, when confined in a harmonic trap, a spin-dependent perturbation can result in the transition between degenerate ground states of $\mathbb{Z}_n$ supersolid. With the integer n tunable using the experimental technique of generating subwavelength optical lattice, the $\mathbb{Z}_n$ supersolid proposed here offers a cold atom platform to simulate physics related with generic $\mathbb{Z}_n$ symmetry breaking in a highly controllable setting.https://doi.org/10.1088/1367-2630/ad98b5supersolidspin–orbit coupled Bose–Einstein condensatepseudo-Goldstone mode |
| spellingShingle | Ze-Hong Guo Qizhong Zhu symmetry broken supersolid in spin–orbit-coupled Bose–Einstein condensates New Journal of Physics supersolid spin–orbit coupled Bose–Einstein condensate pseudo-Goldstone mode |
| title | symmetry broken supersolid in spin–orbit-coupled Bose–Einstein condensates |
| title_full | symmetry broken supersolid in spin–orbit-coupled Bose–Einstein condensates |
| title_fullStr | symmetry broken supersolid in spin–orbit-coupled Bose–Einstein condensates |
| title_full_unstemmed | symmetry broken supersolid in spin–orbit-coupled Bose–Einstein condensates |
| title_short | symmetry broken supersolid in spin–orbit-coupled Bose–Einstein condensates |
| title_sort | symmetry broken supersolid in spin orbit coupled bose einstein condensates |
| topic | supersolid spin–orbit coupled Bose–Einstein condensate pseudo-Goldstone mode |
| url | https://doi.org/10.1088/1367-2630/ad98b5 |
| work_keys_str_mv | AT zehongguo symmetrybrokensupersolidinspinorbitcoupledboseeinsteincondensates AT qizhongzhu symmetrybrokensupersolidinspinorbitcoupledboseeinsteincondensates |