%0 Book Section %1 statphys23_0613 %A Tokuno, A. %A Oshikawa, M. %A Demler, E. %B Abstract Book of the XXIII IUPAP International Conference on Statistical Physics %C Genova, Italy %D 2007 %E Pietronero, Luciano %E Loreto, Vittorio %E Zapperi, Stefano %K aharonov-bohm andreev bose-einstein condensates effect liquids reflection statphys23 tomonaga-luttinger topic-8 %T Universal phenomena of dynamics of one-dimensional Bose liquids: Y-junctions and ring interferometers %U http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=613 %X The guiding of atoms in low-dimensional magnetic traps provides an ideal opportunity to study the coherent quantum dynamics of interacting many-body systems. Recent experiments on the Bose-Einstein condensates (BEC) have been realizing the control of guiding of the atoms. We study the real-time dynamics of the repulsively interacting boson systems. We consider the dynamics of the bosons filled in the Y shaped potential. We calculate the real-time evolution, and investigate the reflection and transmission coefficient at the junction. As a result, we find that, after scattering at the junction, the negative density reflection appears. This reflection is similar to the Andreev-type which can be observed in the metal-superconductor interfaces. We also consider the ring type interferometer filled with the bosons, which consists of two Y-junctions. This is an extension of our analysis of the above single Y-junction problem. In this system, the (effective) magnetic flux exists inside the ring. We assume that the flux just work as the effective gauge field toward the bosons, and never disturb the configuration of the system. If each particle moves independently, when the magnetic flux is a half unit flux quantum, the transmission from one lead to the other lead vanishes. This is a typical example of the Aharonov-Bohm (AB) effect. However, for the interacting bosons, the transport is completely insensitive to the magnetic flux; even if the magnetic flux is a half unit flux quantum, the transmission between leads does not vanish differently form the single particle case. This means the absence of the AB effect. We point out that these interesting behaviors arise from the collective nature of the one-dimensional many body quantum systems. The Andreev-type negative density reflection may be understood in an analogy with a three-way junction of electromagnetic transmission lines (such as coaxial cables). There, an incident signal is reflected at the junction with a negative amplitude in terms of voltage. In our case, reflecting the matter-wave nature of the BEC, the negative amplitude corresponds to a negative variation in the density. The absence of the AB effect also demonstrates clearly the collective nature of the transport, in contrast to the single-particle physics. As long as the systems are described as the TL liquid picture, these phenomena are independent of the strength of the (repulsive) interaction between the bosons. In that sense, they are universal phenomena common to the interacting boson systems in one dimension.

@incollection{statphys23_0613, abstract = {The guiding of atoms in low-dimensional magnetic traps provides an ideal opportunity to study the coherent quantum dynamics of interacting many-body systems. Recent experiments on the Bose-Einstein condensates (BEC) have been realizing the control of guiding of the atoms. We study the real-time dynamics of the repulsively interacting boson systems. We consider the dynamics of the bosons filled in the Y shaped potential. We calculate the real-time evolution, and investigate the reflection and transmission coefficient at the junction. As a result, we find that, after scattering at the junction, the negative density reflection appears. This reflection is similar to the Andreev-type which can be observed in the metal-superconductor interfaces. We also consider the ring type interferometer filled with the bosons, which consists of two Y-junctions. This is an extension of our analysis of the above single Y-junction problem. In this system, the (effective) magnetic flux exists inside the ring. We assume that the flux just work as the effective gauge field toward the bosons, and never disturb the configuration of the system. If each particle moves independently, when the magnetic flux is a half unit flux quantum, the transmission from one lead to the other lead vanishes. This is a typical example of the Aharonov-Bohm (AB) effect. However, for the interacting bosons, the transport is completely insensitive to the magnetic flux; even if the magnetic flux is a half unit flux quantum, the transmission between leads does not vanish differently form the single particle case. This means the absence of the AB effect. We point out that these interesting behaviors arise from the collective nature of the one-dimensional many body quantum systems. The Andreev-type negative density reflection may be understood in an analogy with a three-way junction of electromagnetic transmission lines (such as coaxial cables). There, an incident signal is reflected at the junction with a negative amplitude in terms of voltage. In our case, reflecting the matter-wave nature of the BEC, the negative amplitude corresponds to a negative variation in the density. The absence of the AB effect also demonstrates clearly the collective nature of the transport, in contrast to the single-particle physics. As long as the systems are described as the TL liquid picture, these phenomena are independent of the strength of the (repulsive) interaction between the bosons. In that sense, they are universal phenomena common to the interacting boson systems in one dimension.}, added-at = {2007-06-20T10:16:09.000+0200}, address = {Genova, Italy}, author = {Tokuno, A. and Oshikawa, M. and Demler, E.}, biburl = {https://www.bibsonomy.org/bibtex/211d8bc19df1dbf2b608fa7e86772ff40/statphys23}, booktitle = {Abstract Book of the XXIII IUPAP International Conference on Statistical Physics}, editor = {Pietronero, Luciano and Loreto, Vittorio and Zapperi, Stefano}, interhash = {143dac013f0c82fc9bbfdd374d269cef}, intrahash = {11d8bc19df1dbf2b608fa7e86772ff40}, keywords = {aharonov-bohm andreev bose-einstein condensates effect liquids reflection statphys23 tomonaga-luttinger topic-8}, month = {9-13 July}, timestamp = {2007-06-20T10:16:25.000+0200}, title = {Universal phenomena of dynamics of one-dimensional Bose liquids: Y-junctions and ring interferometers}, url = {http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=613}, year = 2007 }