This brief review summarizes recent theoretical and experimental results which predict and establish the existence of quantum droplets(QDs),i.e.,robust two-and three-dimensional(2D and 3D)self-trapped states in Bose-E...This brief review summarizes recent theoretical and experimental results which predict and establish the existence of quantum droplets(QDs),i.e.,robust two-and three-dimensional(2D and 3D)self-trapped states in Bose-Einstein condensates(BECs),which are stabilized by effective self-repulsion induced by quantum fluctuations around the mean-field(MF)states[alias the Lee-Huang-Yang(LHY)effect].The basic models are presented,taking special care of the dimension crossover,2D→3D.Recently reported experimental results,which exhibit stable 3D and quasi-2D QDs in binary BECs,with the inter-component attraction slightly exceeding the MF self-repulsion in each component,and in single-component condensates of atoms carrying permanent magnetic moments,are presented in some detail.The summary of theoretical results is focused,chiefly,on 3D and quasi-2D QDs with embedded vorticity,as the possibility to stabilize such states is a remarkable prediction.Stable vortex states are presented both for QDs in free space,and for singular but physically relevant 2D modes pulled to the center by the inverse-square potential,with the quantum collapse suppressed by the LHY effect.展开更多
In the course of the past 25 years,several new quantum states of matter have been created in ultracold gases,starting from the celebrated Bose-Einstein condensates(BECs),which were first made in 1995,follow-ing the th...In the course of the past 25 years,several new quantum states of matter have been created in ultracold gases,starting from the celebrated Bose-Einstein condensates(BECs),which were first made in 1995,follow-ing the theoretical prediction published in 1924[1].This achievement was followed by the creation and detailed exploration of degenerate Fermi gases[2].展开更多
We show that Fourier-plane imaging in conjunction with the Kretschmann–Raether configuration can be used for measuring polariton dispersion with spatial discrimination of the sample, over the whole visible spectral r...We show that Fourier-plane imaging in conjunction with the Kretschmann–Raether configuration can be used for measuring polariton dispersion with spatial discrimination of the sample, over the whole visible spectral range.We demonstrate the functionality of our design on several architectures, including plasmonic waveguides, and show that our new design enables the measurement of plasmonic dispersion curves of spatially inhomogeneous structures with features as small as 3 μm, in a single shot.展开更多
Nonlinear frequency conversion of light involves in-teraction of photons through the nonlinear dielec-tric response of mat erials to genera te light at new frequencies.The first demonstration of nonlinear optical freq...Nonlinear frequency conversion of light involves in-teraction of photons through the nonlinear dielec-tric response of mat erials to genera te light at new frequencies.The first demonstration of nonlinear optical frequency conversion was that of second-harmnonic gener-ation(SHG)[1].展开更多
基金Y.L.acknowledges the supports of the National Natural Science Foundation of China(Grant Nos.11874112 and 11905032)the Key Research Projects of General Colleges in Guangdong Province through grant No.2019KZDXM001+1 种基金the Foundation for Distinguished Young Talents in Higher Education of Guangdong through grant No.2018KQNCX279The work of BAM on this topic was supported,in part,by grant No.1286/17 from the Israel Science Foundation.
文摘This brief review summarizes recent theoretical and experimental results which predict and establish the existence of quantum droplets(QDs),i.e.,robust two-and three-dimensional(2D and 3D)self-trapped states in Bose-Einstein condensates(BECs),which are stabilized by effective self-repulsion induced by quantum fluctuations around the mean-field(MF)states[alias the Lee-Huang-Yang(LHY)effect].The basic models are presented,taking special care of the dimension crossover,2D→3D.Recently reported experimental results,which exhibit stable 3D and quasi-2D QDs in binary BECs,with the inter-component attraction slightly exceeding the MF self-repulsion in each component,and in single-component condensates of atoms carrying permanent magnetic moments,are presented in some detail.The summary of theoretical results is focused,chiefly,on 3D and quasi-2D QDs with embedded vorticity,as the possibility to stabilize such states is a remarkable prediction.Stable vortex states are presented both for QDs in free space,and for singular but physically relevant 2D modes pulled to the center by the inverse-square potential,with the quantum collapse suppressed by the LHY effect.
文摘In the course of the past 25 years,several new quantum states of matter have been created in ultracold gases,starting from the celebrated Bose-Einstein condensates(BECs),which were first made in 1995,follow-ing the theoretical prediction published in 1924[1].This achievement was followed by the creation and detailed exploration of degenerate Fermi gases[2].
基金Israel Science Foundation(ISF)(1993/13)FP7 People:Marie-Curie Actions(PEOPLE)(PCIG12-GA-2012-618921)Wolfson Family Charitable Trust(WFCT)(PR/ec/20419)
文摘We show that Fourier-plane imaging in conjunction with the Kretschmann–Raether configuration can be used for measuring polariton dispersion with spatial discrimination of the sample, over the whole visible spectral range.We demonstrate the functionality of our design on several architectures, including plasmonic waveguides, and show that our new design enables the measurement of plasmonic dispersion curves of spatially inhomogeneous structures with features as small as 3 μm, in a single shot.
文摘Nonlinear frequency conversion of light involves in-teraction of photons through the nonlinear dielec-tric response of mat erials to genera te light at new frequencies.The first demonstration of nonlinear optical frequency conversion was that of second-harmnonic gener-ation(SHG)[1].
