Classical rotations of asymmetric rigid bodies are unstable around the axis of intermediate moment of inertia, causing a flipping of rotor orientation. This effect, known as the tennis racket effect, quickly averages to zero in classical ensembles since the flipping period varies significantly upon approaching the separatrix. Here, we explore the quantum rotations of rapidly spinning thermal asymmetric nanorotors and show that classically forbidden tunnelling gives rise to persistent tennis racket dynamics, in stark contrast to the classical expectation. We characterise this effect, demonstrating that quantum coherent flipping dynamics can persist even in the regime where millions of angular momentum states are occupied. This persistent flipping offers a promising route for observing and exploiting quantum effects in rotational degrees of freedom for molecules and nanoparticles.

中文翻译：

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纳米转子的量子持续网球拍动力学

非对称刚体的经典旋转围绕中间惯性矩轴不稳定，从而导致转子方向发生翻转。这种效果被称为网球拍效果，在古典合奏中会很快平均为零，因为翻转周期会在接近分体时发生很大变化。在这里，我们研究了快速旋转的热不对称纳米转子的量子旋转，并显示出经典禁止的隧道效应会产生持久的网球拍动力学特性，这与经典期望形成鲜明对比。我们表征了这种效应，证明了即使在数百万角动量态被占据的状态下，量子相干翻转动力学也可以持续存在。