| 摘要 |
PURPOSE:To control the carrier density of a quantum point contact by altering a voltage applied to the quantum point contact and a gate electrode and to reduce the operating capacity of the electrode by semi-insulating a semiconductor region of a periphery. CONSTITUTION:A semi-insulated region 11 is formed between parts corresponding to first and second main electrodes of a 2-dimensional conductive region, and narrowed to form a quantum point contact region 6. A gate electrode 7 is disposed on the region 11, carrier density in the region 6 is altered in response to a voltage to be applied to the electrode 7 thereby to discretely vary the resistance value between the parts. Thus, the operating capacity of the electrode 7 is reduced. |
