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NbSe3中分离出管状单晶。用聚焦离子束（FIB）铣削方法将晶体切割成多个圆盘。管状单晶沿中轴线有一个孔。切片磁盘的中心也有一个洞。圆盘远离孔的部分使用FIB铣削，靠近孔的部分保留。我们成功地合成了直径为~ 5μm的NbSe3环形样品。通过蒸发铟，将电触点带到环形样品的触点垫上。电阻测量采用四探针法。环形样品的电阻温度依赖性与晶须状单晶的电阻温度依赖性在质量上是相同的。因此，他们确定了环形样品是NbSe3的单晶，在两个转变温度下发生了电荷密度波（CDW）转变，并且通过FIB铣削没有对rin…More g样品产生损伤。在低温CDW状态下，从41K到55K的几个温度范围内观察到CDW滑动的非线性传导。本研究合成的环形样品适合于研究CDW滑动在非线性传导中是否能观察到Aharonov-Bohm （AB）效应。在磁电阻的测量中，将磁场法向施加于环形样品上，并随磁场强度的变化而测量电阻。通过环形样品的总电流保持恒定。电阻作为场强的函数似乎表现为周期性调制。而在恒定磁场和恒定电流下，可以观察到相同幅度的调制。这一事实意味着与磁场调制相比，噪声较大。因此，没有观察到磁电阻的周期性调制。目前还不清楚在CDW滑动的非线性传导中是否可以观察到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