Feshbach blockade: single-photon nonlinear optics using resonantly enhanced cavity-polariton scattering from biexciton states

二维半导体中电磁玻色子的可控融合

Controllable fusion of electromagnetic bosons in two-dimensional semiconductors

本研究提出二维半导体中电磁玻色子可控相互作用的物理原理，利用面内各向异性耦合双激子与散射连续谱，通过磁场或微腔耦合调谐实现共振散射放大与融合，还预测了可制备的Feshbach双聚体巨型分子，为强关联光子学等领域提供新方案。

宽广的费舍克共振在具有大背景散射长度的费米原子-分子混合物中

Broad Feshbach resonance with a large background scattering length in a fermionic atom-molecule mixture

该研究通过观察具有大背景散射长度的费米原子-分子混合物中的宽广费舍克共振，揭示了流体动力学效应在调控费米气体相互作用中的作用。

Resonantly Interacting Fermi-Fermi Mixture of $^{161}$Dy and $^{40}$K

We report on the realization of a Fermi-Fermi mixture of ultracold atoms that combines mass imbalance, tunability, and collisional stability. In an optically trapped sample of $^{161}$Dy and $^{40}$K, we identify a broad Feshbach resonance centered at a magnetic field of $217\,$G. Hydrodynamic expansion profiles in the resonant interaction regime reveal a bimodal behavior resulting from mass imbalance. Lifetime studies on resonance show a suppression of inelastic few-body processes by orders of magnitude, which we interpret as a consequence of the fermionic nature of our system. The resonant m…

Two-Photon Pathway to Ultracold Ground State Molecules of $^{23}$Na$^{40}$K

We report on high-resolution spectroscopy of ultracold fermionic \nak~Feshbach molecules, and identify a two-photon pathway to the rovibrational singlet ground state via a resonantly mixed \Bcres intermediate state. Photoassociation in a $^{23}$Na-$^{40}$K atomic mixture and one-photon spectroscopy on \nak~Feshbach molecules reveal about 20 vibrational levels of the electronically excited \ctrip state. Two of these levels are found to be strongly perturbed by nearby \Bsing states via spin-orbit coupling, resulting in additional lines of dominant singlet character in the perturbed complex {${\r…

Inducing Resonant Interactions in Ultracold Atoms with a Modulated Magnetic Field

In systems of ultracold atoms, pairwise interactions can be resonantly enhanced by a new mechanism which does not rely upon a magnetic Feshbach resonance. In this mechanism, interactions are controlled by tuning the frequency of an oscillating parallel component of the magnetic field close to the transition frequency between the scattering atoms and a two-atom bound state. The real part of the resulting s-wave scattering length $a$ is resonantly enhanced when the oscillation frequency is close to the transition frequency. The resonance parameters can be controlled by varying the amplitude of t…

掺杂过渡金属硫族化物单层中共振增强的极化子介导超导性

Resonantly enhanced polariton-mediated superconductivity in a doped transition metal dichalcogenide monolayer

提出利用激子极化子在单层过渡金属硫族化物中实现光诱导超导性的方案，通过共振激发避开泡利阻塞并利用 Feshbach 共振调节相互作用，有望在较高温度下实现超导。

Composite pairing and superfluidity in a one-dimensional resonant Bose-Fermi mixture

We study the ground-state properties of one-dimensional mixtures of bosonic and fermionic atoms resonantly coupled to fermionic Feshbach molecules. When the particle densities of fermionic atoms and Feshbach molecules differ, the system undergoes various depletion transitions between binary and ternary mixtures, as a function of the detuning parameter. However, when the particle densities of fermionic atoms and Feshbach molecules are identical, the molecular conversion and disassociation processes induce a gap in a sector of low-energy excitations, and the remaining system can be described by …

Resonant control of elastic collisions between $^{23}$Na$^{40}$K molecules and $^{40}$K atoms

We have demonstrated the resonant control of the elastic scattering cross sections in the vicinity of Feshbach resonances between $^{23}$Na$^{40}$K molecules and $^{40}$K atoms by studying the thermalization between them. The elastic scattering cross sections vary by more than two orders of magnitude close to the resonance, and can be well described by an asymmetric Fano profile. The parameters that characterize the magnetically tunable s-wave scattering length are determined from the elastic scattering cross sections. The observation of resonantly controlled elastic scattering cross sections …

Bose polaron interactions in a cavity-coupled monolayer semiconductor

The interaction between a mobile quantum impurity and a bosonic bath leads to the formation of quasiparticles, termed Bose polarons. The elementary properties of Bose polarons, such as their mutual interactions, can differ drastically from those of the bare impurities. Here, we explore Bose polaron physics in a two-dimensional nonequilibrium setting by injecting $σ^-$ polarised exciton-polariton impurities into a bath of coherent $σ^+$ polarised polaritons generated by resonant laser excitation of monolayer MoSe$_2$ embedded in an optical cavity. By exploiting a biexciton Feshbach resonance be…

半导体微腔中的光子量子滴状物

Quantum Droplets of Light in Semiconductor Microcavities

研究在半导体微腔中预测了由激子-光子强耦合形成的极化子量子滴相，通过调节双激子Feshbach共振实现吸引相互作用，为极化子凝聚提供新途径。