We present experimental tests of dissipative extensions of spontaneous wave function collapse models based on a levitated micromagnet with ultralow dissipation. The spherical micromagnet, with a radius $R=27\mu \mathrm{m}$, is levitated by the Meissner effect in a lead trap at $4.2\mathrm{K}$ and its motion is detected by a superconducting quantum interference device. We perform accurate ringdown measurements on the vertical translational mode with frequency $57\mathrm{Hz}$ and infer the residual damping at vanishing pressure $\gamma /2\pi <9\mu \mathrm{Hz}$. From this upper limit we derive improved bounds on the dissipative versions of the continuous spontaneous localization (CSL) and the Diósi-Penrose (DP) models with proper choices of the reference mass. In particular, dissipative models give rise to an intrinsic damping of an isolated system with the effect parametrized by a temperature constant; the dissipative CSL model with temperatures below 1 nK is ruled out, while the dissipative DP model is excluded for temperatures below ${10}^{-13}\mathrm{K}$. Furthermore, we present the bounds on dissipative effects in a more recent model, which relates the wave function collapse to fluctuations of a generalized complex-valued space-time metric.

中文翻译：

---

用悬浮微磁体测试耗散塌陷模型

我们提出了基于具有超低耗散的悬浮微磁体的自发波函数崩溃模型的耗散扩展的实验测试。球形微磁铁，半径$\mathrm{[R}=27\mu \mathrm{米}$，被迈斯纳效应悬浮在一个铅阱中 $4.2\mathrm{ķ}$它的运动由超导量子干涉装置检测。我们在垂直平移模式下以频率执行精确的振铃测量$57\mathrm{赫兹}$ 并推断出消失压力下的剩余阻尼 $\gamma /2\pi <9\mu \mathrm{赫兹}$。从这个上限，我们推导出在连续自发定位（CSL）和Diósi - 彭罗斯（DP）与基准质量的正确选择模型的耗散版本改进边界。尤其是，耗散模型会导致隔离系统的固有阻尼，其作用由温度常数来参数化。排除了温度低于1 nK的耗散CSL模型，而温度低于1 nK则排除了耗散DP模型${10}^{-13}\mathrm{ķ}$。此外，我们在最近的模型中给出了耗散效应的界限，该模型将波函数崩溃与广义复数值时空度量的波动相关。