Quantum walk and Anderson localization of rotational excitations in disordered ensembles of polar molecules
We consider the dynamics of rotational excitations placed on a single molecule in spatially disordered one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) ensembles of ultracold molecules trapped in optical lattices. The disorder arises from incomplete populations of optical lattic...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2015-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/17/6/065014 |
| _version_ | 1797751170619408384 |
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| author | T Xu R V Krems |
| author_facet | T Xu R V Krems |
| author_sort | T Xu |
| collection | DOAJ |
| description | We consider the dynamics of rotational excitations placed on a single molecule in spatially disordered one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) ensembles of ultracold molecules trapped in optical lattices. The disorder arises from incomplete populations of optical lattices with molecules. This leads to a model corresponding to a quantum particle with long-range tunnelling amplitudes moving on a lattice with the same on-site energy but with forbidden access to random sites (vacancies). We examine the time and length scales of Anderson localization for this type of disorder with realistic experimental parameters in the Hamiltonian. We show that for an experimentally realized system of KRb molecules on an optical lattice this type of disorder leads to disorder-induced localization in 1D and 2D systems on a time scale $t\sim 1$ s. For 3D lattices with 55 sites in each dimension and vacancy concentration 90%, the rotational excitations diffuse to the edges of the lattice and show no signature of Anderson localization. We examine the role of the long-range tunnelling amplitudes allowing for transfer of rotational excitations between distant lattice sites. Our results show that the long-range tunnelling has little impact on the dynamics in the diffusive regime but affects significantly the localization dynamics in lattices with large concentrations of vacancies, enhancing the width of the localized distributions in 2D lattices by more than a factor of 2. |
| first_indexed | 2024-03-12T16:43:36Z |
| format | Article |
| id | doaj.art-812030eab0ca464091f657284c1402ec |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:43:36Z |
| publishDate | 2015-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-812030eab0ca464091f657284c1402ec2023-08-08T14:19:37ZengIOP PublishingNew Journal of Physics1367-26302015-01-0117606501410.1088/1367-2630/17/6/065014Quantum walk and Anderson localization of rotational excitations in disordered ensembles of polar moleculesT Xu0R V Krems1Department of Chemistry, University of British Columbia , Vancouver, BC V6T 1Z1, CanadaDepartment of Chemistry, University of British Columbia , Vancouver, BC V6T 1Z1, CanadaWe consider the dynamics of rotational excitations placed on a single molecule in spatially disordered one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) ensembles of ultracold molecules trapped in optical lattices. The disorder arises from incomplete populations of optical lattices with molecules. This leads to a model corresponding to a quantum particle with long-range tunnelling amplitudes moving on a lattice with the same on-site energy but with forbidden access to random sites (vacancies). We examine the time and length scales of Anderson localization for this type of disorder with realistic experimental parameters in the Hamiltonian. We show that for an experimentally realized system of KRb molecules on an optical lattice this type of disorder leads to disorder-induced localization in 1D and 2D systems on a time scale $t\sim 1$ s. For 3D lattices with 55 sites in each dimension and vacancy concentration 90%, the rotational excitations diffuse to the edges of the lattice and show no signature of Anderson localization. We examine the role of the long-range tunnelling amplitudes allowing for transfer of rotational excitations between distant lattice sites. Our results show that the long-range tunnelling has little impact on the dynamics in the diffusive regime but affects significantly the localization dynamics in lattices with large concentrations of vacancies, enhancing the width of the localized distributions in 2D lattices by more than a factor of 2.https://doi.org/10.1088/1367-2630/17/6/065014quantum walkAnderson localizationultracold moleculesdisorder-induced localization |
| spellingShingle | T Xu R V Krems Quantum walk and Anderson localization of rotational excitations in disordered ensembles of polar molecules New Journal of Physics quantum walk Anderson localization ultracold molecules disorder-induced localization |
| title | Quantum walk and Anderson localization of rotational excitations in disordered ensembles of polar molecules |
| title_full | Quantum walk and Anderson localization of rotational excitations in disordered ensembles of polar molecules |
| title_fullStr | Quantum walk and Anderson localization of rotational excitations in disordered ensembles of polar molecules |
| title_full_unstemmed | Quantum walk and Anderson localization of rotational excitations in disordered ensembles of polar molecules |
| title_short | Quantum walk and Anderson localization of rotational excitations in disordered ensembles of polar molecules |
| title_sort | quantum walk and anderson localization of rotational excitations in disordered ensembles of polar molecules |
| topic | quantum walk Anderson localization ultracold molecules disorder-induced localization |
| url | https://doi.org/10.1088/1367-2630/17/6/065014 |
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