[講演者] 千葉侑哉氏 （東大総合文化）

[日時] 7月1日(月) 16:30-

[場所]物理学科会議室

[タイトル] Anomalous behaviors of magnetic susceptibility obtained by experiments on isolated quantum systems

[アブストラクト]

In this work we study the wavenumber (k) dependence of magnetic susceptibility which will be obtained by experiments on isolated quantum systems. We find that it has discontinuity at k=0, i.e., the k=0 value is different from the limit of k -> 0.

We compare the k=0 value and the limiting value with the two thermodynamic susceptibilities, the adiabatic one and the isothermal one. We find that the ETH and related conditions determine which susceptibility agrees with the susceptibility of isolated system.

We illustrate these points by taking the XYZ, XXZ and XY chains as examples. By changing the parameters from integrable (XXZ, XY) to non-integrable (XYZ) values, and by changing k, we clearly observe that the isolated susceptibility takes different values and only some of them agree with either of the thermodynamic susceptibilities.