Billangeon P-M, Pierre F, Bouchiat H, Deblock R
Laboratoire de Physique des Solides, Université Paris-Sud, CNRS, UMR 8502, F-91405 Orsay Cedex, France.
Phys Rev Lett. 2007 Mar 23;98(12):126802. doi: 10.1103/PhysRevLett.98.126802. Epub 2007 Mar 20.
A single-Cooper-pair transistor (SCPT) is coupled capacitively to a voltage biased Josephson junction, used as a high-frequency generator. Thanks to the high energy of photons generated by the Josephson junction, transitions between energy levels, not limited to the first two levels, were induced and the effect of this irradiation on the dc Josephson current of the SCPT was measured. The phase and gate bias dependence of energy levels of the SCPT at high energy is probed. Because the energies of photons can be higher than the superconducting gap we can induce not only transfer of Cooper pairs but also transfer of quasiparticles through the island of the SCPT, thus controlling the poisoning of the SCPT. This can both decrease and increase the average Josephson energy of the SCPT: its supercurrent is then controlled by high-frequency irradiation.
单库珀对晶体管（SCPT）通过电容耦合到一个电压偏置的约瑟夫森结，该约瑟夫森结用作高频发生器。由于约瑟夫森结产生的光子能量很高，诱导了不限于前两个能级的能级之间的跃迁，并测量了这种辐照对SCPT直流约瑟夫森电流的影响。研究了SCPT在高能情况下能级的相位和栅极偏置依赖性。由于光子能量可以高于超导能隙，我们不仅可以诱导库珀对的转移，还可以诱导准粒子通过SCPT的岛转移，从而控制SCPT的中毒。这既可以降低也可以增加SCPT的平均约瑟夫森能量：其超电流随后由高频辐照控制。
