Two seminars this week

[Cond.Matt. & Stat.Mech.Section]

SEMINAR on   Disorder and strong electron correlations

 

Thursday, 7 March -  11:30 a.m.



Luigi Stasi Seminar Room,  Leonardo Building - first floor

 

John GOOLD    (University of Oxford)
 

"Utility and detection of   work fluctuation theorems in many-body physics"



Abstract


The statistics of work done and associated fluctuation theorems give a novel thermodynamic interpretation of dynamics in quantum systems. Here, we apply the fluctuation theorems to a sudden "quench" of a quantum system of many interacting particles containing a critical point.  The results highlight that the fluctuations of a dynamical quantum system provide a route understanding the emergence of thermodynamic irreversibility. Furthermore I will show that the characteristic function of the work distribution for a non-equilibrium process can be extracted from Ramsey interferometry of a single probe qubit. Our scheme paves the way for the full characterisation of non-equilibrium processes in a variety of complex quantum systems, ranging from atomic systems to NMR.

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JOINT ICTP/SISSA   COLLOQUIUM   ON CONDENSED MATTER PHYSICS

 

Friday, 8 March -  11:30 a.m.

 


Luigi Stasi Seminar Room    ICTP Leonardo Building (1st floor)

 

Kunio TAKAYANAGI    ( Tokyo Institute of Technology )



" Lithium ions in   spinel (LiMn2O4, LiV2O4) nanowire "

 
Abstract

 
Lithium ion transport attracts much interest because it is fundamental process at lithium ion battery electrodes, particularly at nanowire electrodes. To study irreversible transport process at charging–discharging process directly at atomic scale, we developed an aberration corrected electron microscope which allows us to form an electron probe having a diameter of sub-50pm. The spherical electron wave emitting from the electron probe scans the specimen surface was found for the first time to give structure image of individual lithium ions. In electrodes of spinel structure, i.e., LiMn2O4, dislocation of lithium ions from the tetrahedral sites induces local structure change at octahedral sites, which makes charging-discharging cycle of ion transport irreversible#). Structure change is discussed in relation to the current-voltage relation of a mode LIB. At excess or deficient concentration of lithium ions, spinel electrodes exhibited local disorder. To characterize local disorder, we devised a new method which can allow us to find not only pair correlation but also higher order correlation of the local disorder.

#)This work is supported by CREST project, “nanocycle at nano-in-macro interface”