A low-temperature high-sensitivity torsion balance magnetometer with in situ stator adjustment
A low-temperature high-sensitivity torsion balance magnetometer with in situ stator adjustment
复制标题
定子原位调节低温高灵敏度扭平衡磁力计
DOI：
10.1063/1.1771494
复制
发表时间：
2004
影响因子：
1.6
通讯作者：
C. D. Williams
中科院分区：
文献类型：
--
作者：
A. Matthews;A. Usher;C. D. Williams
扭转平衡磁力仪可作为二维电子系统的多功能探针。我们已经开发出一种高灵敏度的磁力计，利用电容接近检测的转子位置，在温度低于10 mK的使用。 该仪器集成了两个压电线性电机，使定子位置能够在基础温度下进行原位调整。磁力计的响应度与转子-定子间距的平方成反比，并且新型线性电机技术，伴随着有效的振动隔离和优化的电容桥电子器件，实现了6.5×10−12 N m Hz− 12的分辨率。 这种分辨率，再加上可达到的低温，允许实验探测负责分数量子霍尔效应的量子流体状态的家庭，即使在填充因子大于一。
Torsion balance magnetometry can be used as a versatile probe of two-dimensional electron systems. We have developed a highly sensitive magnetometer, utilizing capacitive proximity detection of the rotor position, for use at temperatures below 10 mK. The instrument incorporates two piezo-electric linear motors to enable the stator positions to be adjusted in situ at base temperature. The magnetometer responsivity is inversely proportional to the square of the rotor–stator separation and the novel linear motor technique, accompanied by effective vibration isolation and optimized capacitance bridge electronics, achieves a resolution 6.5×10−12 N m Hz−1/2. This resolution, together with the low temperatures attainable, allows for experiments that probe the family of quantum fluid states responsible for the fractional quantum Hall effect, even at filling factors greater than one.