Speaker
Description
We study the one-dimensional (1D) transport properties of an ultracold gas of Bose-Einstein con- densed atoms through Aharonov-Bohm (AB) rings [1–3]. Our system consists of a Bose-Einstein condensate (BEC) that is outcoupled from a magnetic trap into a 1D waveguide which is made of two semi-infinite leads that join a ring geometry exposed to a synthetic magnetic flux φ. We specifically investigate the effects both of a disorder potential and of a small atom-atom contact in- teraction strength on the AB oscillations. The main numerical tools that we use for this purpose are a mean-field Gross-Pitaevskii (GP) description and the truncated Wigner (tW) method [4, 5]. The latter allows for the description of incoherent transport and corresponds to a classical sampling of the evolution of the quantum bosonic many-body state through effective GP trajectories. We find that a correlated disorder suppress the AB oscillations leaving thereby place to weaker amplitude, half period oscillations on transmission, namely the Aronov-Al’tshuler-Spivak (AAS) oscillations [6, 7]. The competition between disorder and interaction leads to a flip of the transmission at the AB flux φ = π. This flip could be a possible preliminary signature of an inversion of the coherent backscat- tering peak [8, 9].
References
[1] R.A. Webb, S. Washburn, C.P. Umbach and R.B. Laibowitz, Phys. Rev. Lett. 54, 2696 (1985).
[2] A. Levy Yeyati and M. Büttiker, Phys. Rev. B 52, R14360 (1995).
[3] H. Sigurdsson, O. V. Kibis, and I. A. Shelykh, Phys. Rev. B 90, 235413 (2014).
[4] C. W. Gardiner and P. Zoller, Quantum Noise, Springer (2004).
[5] J. Dujardin, A. Argüelles, and P. Schlagheck, Phys. Rev. A 91, 033614 (2015).
[6] B.L. Al’tshuler, A.G. Aronov, and B.Z. Spivak, JETP Lett. 33 (1993).
[7] D. Yu. Sharvin and Yu. V. Sharvin, JETP Lett. 34 (1981).
[8] M. Hartung, T. Wellens, C. A. Müller, K. Richter, and P. Schlagheck, Phys. Rev. Lett. 101, 020603 (2008).
[9] T. Wellens and B. Grémaud, Phys. Rev. Lett. 100, 033902 (2008).
