Ways to Mitigate Decoherence in Solitonic Schroedinger Cats

宏观系统的观察态很少表现出明显的量子特征。这通常归因于退相干效应；也就是，不受控制的环境变量的影响，这些变量将量子奇异性“平均”出来。这个项目是利用玻色-爱因斯坦凝聚体中产生的孤子(非线性波)实现宏观量子态的长期努力的延续。当这样的波从势垒上散射出来时，它就会分裂成两个部分：一个是越过势垒的高频部分，另一个是被反射的低频部分。要研究的问题是，这两个分量是否以及在什么条件下保持量子相干。宏观量子相干性在现代物理学中具有特殊的地位。虽然这是最基本但未经检验的假设之一，但它有望使量子传感器的灵敏度提高数倍。这个项目建立在一个猜想的基础上，即对于一个孤子中数量很大但数量有限的原子，大型孤子薛定谔猫可以出现在看似对平均场友好的参数范围内。这一猜想将由研究生使用各种计算方法在理论上进行探索。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Observed states of macroscopic systems seldom exhibit obvious quantum characteristics. This is usually attributed to the effects of decoherence; that is, the influence of uncontrolled environmental variables which "average out" the quantum strangeness. This project is the continuation of a long-term effort to realize macroscopic quantum states using solitons (non-linear waves) generated in Bose-Einstein condensates. When such a wave is scattered from a potential barrier, it breaks into two; a high-frequency part that transcends the barrier, and a low-frequency part that is reflected. The question to be studied is whether, and under what conditions, the two components retain quantum coherence. Macroscopic quantum coherence plays a special role in modern physics. While being one of the most fundamental but untested assumptions, it promises a multifold increase in sensitivity of quantum sensors. This project is founded on a conjecture that large solitonic Schroedinger cats can emerge within a seemingly mean-field friendly range of parameters, for a large but limited number of atoms in a soliton. The conjecture will be theoretically explored by graduate students using a variety of computational methods.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.