The Aharonov-Bohm effect of the charge-density wave in ring-shaped crystals of quasi-one dimensional conductors

从一批准一维导体NbSe 3中取出管状单晶。通过聚焦离子束（FIB）研磨将晶体切成几个圆盘。管状单晶具有沿中心轴沿着的孔。切片的圆盘在其中心也有一个孔。使用FIB铣削远离孔的盘的部分，并且保留靠近孔的部分。我们成功地合成了直径为1.5 μm的NbSe_3环形样品。通过蒸发铟将电触点带到环样品的接触垫。用四探针法测量了环形样品的电阻，其电阻随温度的变化与晶须状单晶的电阻随温度的变化定性相同。因此，可以确定环形样品是NbSe_3的单晶，在两个转变温度下发生电荷密度波（CDW）转变，并且没有对环形样品造成损伤 关于我们 g样品通过FIB研磨。在41 ~ 55 K的温度范围内，观察到低温CDW态的非线性导电行为。本文合成的环形样品适合于研究在CDW滑动的非线性导电中是否能观察到Aharonov-Bohm（AB）效应。通过环形样品的总电流保持恒定。电阻随场强的变化呈现出周期性的调制。而在恒磁场和恒电流下，则观察到了相同幅度的调制。这一事实意味着与磁场调制相比，噪声较大。因此，没有观察到磁阻的周期性调制，也不清楚在CDW滑动的非线性导电中是否能观察到AB效应。需要提高信噪比。少

A tube-shaped single crystal was taken out from a batch of the quasi-one-dimensional conductor NbSe3. The crystal was sliced into several disks by focused ion beam (FIB) milling. Tube-shaped single crystals have a hole along the center axis. The sliced disks also have a hole at the center of them. The part of the disk away from the hole was milled using FIB, and the part near the hole was remained. We have successfully synthesized a ring sample of NbSe3 with a diameter of 〜5μm. The electrical contacts, were taken to the contact pads of the ring sample by evaporating indium. Measurements of resistance were performed by the four-probe method.Temperature dependence of resistance of the ring sample has been qualitatively the same as that of the whisker-shaped single crystals. Therefore, they are certain that the ring sample is the single crystal of NbSe3, that the charge-density-wave (CDW) transitions take place at the two transition temperatures, and that no damage is induced into the rin … More g sample through the FIB milling. The nonlinear conduction by the CDW sliding has been observed at several temperatures from 41K to 55K in the low-temperature CDW state. The ring sample synthesized in this study is suitable for studying whether the Aharonov-Bohm (AB) effect can be observed in the nonlinear conduction by the CDW sliding.In the measurements of magnetoresistance, the magnetic field was applied normal to the ring sample and the resistance was measured with changing strength of the magnetic field. The total current through the ring sample was kept constant. The resistance as a function of field strength seemed to show a periodic modulation. However, the modulation with the same amplitude was observed under the constant magnetic fields and constant currents. This fact means that the noise is large compared to the modulation by the magnetic field. Therefore, the periodic modulation of the magnetoresistnce has not been observed.It is not clarified whether the AB effect can be observed in the nonlinear conduction by the CDW sliding. It is needed that the signal-to-noise ratio is improved. Less