We demonstrate a method for measuring atom-surface interactions using transmission spectroscopy of thermal vapors confined in a wedged nanocell. The wedged shape of the cell allows complementary measurements of both the bulk atomic vapor and atoms close to surfaces experiencing strong van der Waals atom-surface interaction. These are used to tightly constrain the dipole-dipole collisional parameters of a theoretical model for transmission spectra that accounts for atom-surface interactions, cavity effects, collisions with the surface of the cell, and atomic motion. We illustrate this method on a cesium vapor in a sapphire cell, demonstrating that even the weakest of the van der Waals atom-surface interaction coefficients---for ground-state alkali atom transitions---can be determined with a very good precision. This result paves the way towards a precise quantitative characterization of atom-surface interactions in a wide range of atom-based nanodevices.We demonstrate a method for measuring atom-surface interactions using transmission spectroscopy of thermal vapors confined in a wedged nanocell. The wedged shape of the cell allows complementary measurements of both the bulk atomic vapor and atoms close to surfaces experiencing strong van der Waals atom-surface interaction. These are used to tightly constrain the dipole-dipole collisional parameters of a theoretical model for transmission spectra that accounts for atom-surface interactions, cavity effects, collisions with the surface of the cell, and atomic motion. We illustrate this method on a cesium vapor in a sapphire cell, demonstrating that even the weakest of the van der Waals atom-surface interaction coefficients---for ground-state alkali atom transitions---can be determined with a very good precision. This result paves the way towards a precise quantitative characterization of atom-surface interactions in a wide range of atom-based nanodevices.

arXiv:1905.02783Physical Review AAug 1, 201931 citations

Polarization entanglement enabled by orthogonally stacked van der Waals NbOCl2 crystals

Qiangbing Guo, Yunkun Wu, Di Zhang +5 more

Polarization entanglement holds significant importance for photonic quantum technologies. Recently emerging subwavelength nonlinear quantum light sources, e.g., GaP and LiNbO3 thin films, benefiting from the relaxed phase-matching constraints and volume confinement, have shown intriguing properties, such as high-dimensional hyperentanglement and robust entanglement anti-degradation. Van der Waals (vdW) NbOCl2 crystal, with strong optical nonlinearities, has emerged as a potential candidate for ultrathin quantum light sources. However, polarization entanglement is inaccessible in the NbOCl2 crystal due to its unfavorable nonlinear susceptibility tensor. Here, by leveraging the twist-stacking degree of freedom inherently in vdW systems, we showcase the preparation of polarization entanglement and quantum Bell states. Van der Waals NbOCl2 crystal is a candidate platform for subwavelength thin film photon-pair sources. Here, the authors demonstrate generation of polarization entangled states from a two-layer stack of orthogonally oriented van der Waals crystal.Polarization entanglement holds significant importance for photonic quantum technologies. Recently emerging subwavelength nonlinear quantum light sources, e.g., GaP and LiNbO3 thin films, benefiting from the relaxed phase-matching constraints and volume confinement, have shown intriguing properties, such as high-dimensional hyperentanglement and robust entanglement anti-degradation. Van der Waals (vdW) NbOCl2 crystal, with strong optical nonlinearities, has emerged as a potential candidate for ultrathin quantum light sources. However, polarization entanglement is inaccessible in the NbOCl2 crystal due to its unfavorable nonlinear susceptibility tensor. Here, by leveraging the twist-stacking degree of freedom inherently in vdW systems, we showcase the preparation of polarization entanglement and quantum Bell states. Van der Waals NbOCl2 crystal is a candidate platform for subwavelength thin film photon-pair sources. Here, the authors demonstrate generation of polarization entangled states from a two-layer stack of orthogonally oriented van der Waals crystal.

arXiv:2408.06751Nature CommunicationsDec 2, 202431 citations

Supersonic Molecular Beams and van der Waals Molecules

Donald Harris Levy

Springer eBooksJan 1, 19803 citations

Stereodynamics Effects on van der Waals Molecule Formation Through Three-Body Recombination

Yu Wang, Jesús Pérez‐Ríos

Abstract In this work, we present a study on the role of atomic configurations in forming van der Waals molecules through three-body recombination. Fixing the angle between the two momenta associated with the Jacobi vectors, we calculate the reaction probability for a specific configuration. In this way, we elucidate the nature of the total reaction probability in reactions X + He + He $\rightarrow$ XHe + He, which is essential for understanding van der Waals molecules formation in molecular beams and buffer gas cells.Abstract In this work, we present a study on the role of atomic configurations in forming van der Waals molecules through three-body recombination. Fixing the angle between the two momenta associated with the Jacobi vectors, we calculate the reaction probability for a specific configuration. In this way, we elucidate the nature of the total reaction probability in reactions X + He + He$\rightarrow$XHe + He, which is essential for understanding van der Waals molecules formation in molecular beams and buffer gas cells.

Few-Body SystemsAug 31, 20241 citation

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XHe + He, which is essential for understanding van der Waals molecules formation in molecular beams and buffer gas cells.