CAREER: Making a Difference in First Generation and Underrepresented Students' Education through Research: Quantum Coherence in a Bose Thermal Gas

冷原子气体是量子计算和精密传感器应用的有希望的候选者，因为它们在低温下表现出波动性和相干性。完全相干的样品，所谓的“量子气体”，在冷却到接近绝对零度时实现，但这在技术上具有挑战性。然而，最近的研究表明，即使在温度远高于产生量子气体所需温度的热气体中，内部量子相干性也可以持续存在。该项目的第一个目标是确定在这些热气体中保持量子相干性的限制条件。因此，它将探索经典和量子机制之间的边界，并可能有助于低成本量子技术的发展。第二个目标是研究这种气体从热云到量子气体的转变。根据实验条件的不同，量子特性可以被抑制或增强，从而影响计算的复杂性和测量的精度。该项目的第三个目标是将量子科学研究融入本科教育。如果成功，这将提供一个模型，使量子科学研究更容易进入本科生的机构，为物理学中代表性不足的群体提供增强的学习机会。实验研究计划将测量超冷原子旋量气体，主要目标有三个。该项目的第一个目标是确定玻色热气体表现出相干自旋变化碰撞的最高温度。旋量气体的全光捕获将被用来探测样品的旋量动力学作为温度的函数。热气体将与所需的初始自旋状态相干制备，并将通过磁子能级的吸收成像来测量由此产生的粒子数振荡。第二，该项目将研究在热气体转变为玻色-爱因斯坦凝聚体的温度范围内的相干自旋变化碰撞。虽然极限情况是很好理解的，目前还没有理论模型来描述这个中间政权。有人认为，例如，热和玻色凝聚成分之间的自旋锁定可以导致热云相干性的增强或抑制。相干性的损失限制了量子信息系统中计算的复杂性和测量的精度。实验研究将提供所需的测量，以开发准确的理论模型。第三，该项目将整合量子物理学的教育和研究，降低技术要求，主要适用于本科院校，为代表性不足的群体提供更多的学习机会。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Cold atomic gases are promising candidates for applications in quantum computing and precision sensors, owing to their wave-like, coherent nature exhibited at low temperatures. Fully-coherent samples, so-called “quantum gases”, are achieved when cooled to near absolute zero, but this is technically challenging. Recent work, though, has demonstrated that internal quantum coherence can persist even in thermal gases whose temperatures are well above those required to create a quantum gas. The first goal of this project is to determine the limiting conditions for which quantum coherence is preserved in these thermal gases. As such, it will probe the boundary between the classical and quantum regimes and may aid in the development of low-cost quantum technologies. The second goal is to investigate such a gas as it transitions from a thermal cloud to a quantum gas. Depending on the conditions of the experiment, the quantum properties can be either suppressed or enhanced, affecting the complexity of computations and the precision of measurements. The third goal of this project is to integrate quantum science research into undergraduate education. If successful, this will provide a model to make quantum science research more accessible to undergraduate-only institutions, providing enhanced learning opportunities to underrepresented groups in physics. The experimental research program will measure ultracold atomic spinor gases with three main goals. The first goal of the project is to determine the maximum temperature for a Bose thermal gas to exhibit coherent spin-changing collisions. All-optical trapping of spinor gases will be utilized to probe the spinor dynamics of samples as a function of temperature. A thermal gas will be coherently prepared with the desired initial spin state, and the resulting population oscillations will be measured through absorption imaging of the magnetic sublevels. Second, the project will investigate coherent spin-changing collisions in the temperature regime as a thermal gas transitions to a Bose-Einstein condensate. Although the limiting cases are well-understood, there is currently no theoretical model to describe this intermediate regime. It has been argued that spin-locking between the thermal and Bose-condensed components, for example, can lead to either an enhancement or suppression of the coherence of the thermal cloud. The loss of coherence limits the complexity of computation in quantum information systems and the precision of measurements. Experimental studies will provide needed measurements to develop accurate theoretical models. Third, the project will integrate education and research in quantum physics with reduced technical requirements suitable for primarily undergraduate institutions, providing enhanced learning opportunities for underrepresented groups.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.