QFS2016 Book of Abstracts

Abstracts

P4.24 Ground state energy for a Lieb-Liniger gas within a multi-rods structure: Variational Monte Carlo vs Mean-Field calculations O.A. Rodr´ıguez(1,2), M.A. Sol´ıs(2) 1) Universidad Nacional Aut´onoma de M´exico, Posgrado en Ciencias F´ısicas 2) Universidad Nacional Aut´onoma de M´exico, Instituto de F´ısica We use the Variational Monte Carlo (VMC) method to calculate the groun state energy of an interacting Bose gas constrained by an one-dimensional periodic multi-rods structure created by applying an external Kronig-Penney potential. Our variational results are compared with those we previously obtained using the Mean-Field approximation [1] where we analytically solve the Gross-Pitaevskii equation. In the limit of zero external potential, we recover the well-known Lieb-Liniger gas, which becomes the Tonks gas for strong interactions. In this case we compare our variational results with those obtained originally by Lieb and Liniger [2], as well as with those calculated by means of the Diffusion Monte Carlo (DMC) method [3]. Only in the region of high density and weak interaction, Mean-Field results are equal to DMC results and better than the variational ones. [1] O.A. Rodr´ıguez and M.A. Sol´ıs, “Ground state of a Lieb-Liniger gas within multi-rods solving analytically the Gross-Pitaevskii equation”, work in process. [2] E.H. Lieb and W. Liniger, PR 130 , 1605 (1963). [3] G.E. Astrakharchik and S. Giorgini, PRA 68 , 031602 (2003). We thanks partial support from grants CONACyT 221030 and PAPIIT IN107616. P4.25 Quantum-limited heat conduction over macroscopic distances Tan, Kuan Yen(1) Partanen, Matti(1) Govenius, Joonas(1) Lake, Russell E.(1) M¨akel¨a, Miika K.(1) Tanttu, Tuomo(1) M¨ott¨onen, Mikko(1). 1) QCD Labs, COMP Centre of Excellence, Department of Applied Physics, Aalto University. We present experimental observations of quantum-limited heat conduction over macroscopic distances extending to a metre. We achieved this improvement of four orders of magnitude in the distance by utilizing microwave photons travelling in superconducting transmission lines. This suggests that quantum-limited heat conduction has no fundamental distance cutoff. This work establishes the integration of normal-metal components into the framework of circuit quantum electrodynamics, which provides a basis for the superconducting quantum computer. In particular, our results facilitate remote cooling of nanoelectronic devices using faraway in situ-tunable heat sinks.

127