Negative Differential Conductivity in an Interacting Quantum Gas.
We report on the observation of negative differential conductivity (NDC) in a quantum transport device for neutral atoms employing a multimode tunneling junction. The system is realized with a Bose-Einstein condensate loaded in a one-dimensional optical lattice with high site occupancy. We induce an initial difference in chemical potential at one site by local atom removal. The ensuing transport dynamics are governed by the interplay between the tunneling coupling, the interaction energy, and intrinsic collisions, which turn the coherent coupling into a hopping process. The resulting current-voltage characteristics exhibit NDC, for which we identify atom number-dependent tunneling as a new microscopic mechanism. Our study opens new ways for the future implementation and control of complex neutral atom quantum circuits.
Research Center OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.|Graduate School Materials Science in Mainz, Staudinger Weg 9, 55128 Mainz, Germany.
Ralf
R
Labouvie
Research Center OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.
Bodhaditya
B
Santra
Research Center OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.
Simon
S
Heun
DiFeST, Università di Parma, Via G. P. Usberti 7/a, 43124 Parma, Italy.|INFN, Sezione di Milano Bicocca, Gruppo Collegato di Parma, 43124 Parma, Italy.
Sandro
S
Wimberger
Research Center OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.
Herwig
H
Ott