标题： 控制超冷偶极分子的散射长度 显示英文标题

标题： Controlling the scattering length of ultracold dipolar molecules

摘要： 通过应用相对于偶极分子第一激发旋转态的圆偏振且略微蓝频移的微波场，可以在两个碰撞粒子的入口通道中设计出一个长程、浅势阱。 随着所施加的微波交流场的增加，长程势阱变得更深，并可以支持一定数量的束缚态，这反过来会将分子-分子散射长度的值从大的负值变为大的正值。 我们采用了一种无量纲方法，其中分子由归一化的旋转常数$\tilde{B} = B/s_{E_3} $描述，其中$s_{E_3}$是一个特征偶极能量。 我们发现，当施加足够的交流场时，具有$\tilde{B} > 10^8$的分子对任何淬灭损失都是免疫的，弹性过程与淬灭过程的比值可以达到高于$10^3$的值，并且散射长度的值和符号可以被调节。 控制分子散射长度的能力为超冷分子开启了丰富且强关联的多体物理现象，类似于超冷原子的情况。 显示英文摘要

摘要： By applying a circularly polarized and slightly blue-detuned microwave field with respect to the first excited rotational state of a dipolar molecule, one can engineer a long-range, shallow potential well in the entrance channel of the two colliding partners. As the applied microwave ac-field is increased, the long-range well becomes deeper and can support a certain numbers of bound states, which in turn bring the value of the molecule-molecule scattering length from a large negative value to a large positive one. We adopt an adimensional approach where the molecules are described by a rescaled rotational constant $\tilde{B} = B/s_{E_3} $ where $s_{E_3}$ is a characteristic dipolar energy. We found that molecules with $\tilde{B} > 10^8$ are immune to any quenching losses when a sufficient ac-field is applied, the ratio elastic to quenching processes can reach values above $10^3$, and that the value and sign of the scattering length can be tuned. The ability to control the molecular scattering length opens the door for a rich, strongly correlated, many-body physics for ultracold molecules, similar than that for ultracold atoms.