Elastic anomaly of helium films at a quantum phase transition
Elastic anomaly of helium films at a quantum phase transition
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量子相变时氦膜的弹性异常
DOI：
10.1103/physrevb.98.235104
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发表时间：
2018
影响因子：
3.7
通讯作者：
Shirahama K.
中科院分区：
文献类型：
--
作者：
Makiuchi T.;Tagai M.;Nago Y.;Takahashi D.;Shirahama K.
氦膜显示出各种量子相，通过改变覆盖范围来经历量子相变。我们发现吸附在玻璃基板上的玻色子和费米子薄膜存在异常弹性现象。薄膜在低温下的交流应变下变硬，并产生过多的耗散。当接近临界覆盖范围时，硬化起始温度降低至 0 K。弹性异常可以通过氦原子从局域态热激活到具有分布式能隙的扩展态来解释。我们根据弹性确定氦膜的能带结构。 andat 的基态可能是一种莫特绝缘体或莫特玻璃，具有相同的间隙和可压缩性。
Helium films show various quantum phases that undergo quantum phase transitions by changing coverage. We found anomalous elastic phenomena in bosonicand fermionicfilms adsorbed on a glass substrate. The films stiffen under ac strain at low temperature with an excess dissipation. The onset temperature of the stiffening decreases to 0 K asapproaches a critical coverage. The elastic anomaly is explained by thermal activation of helium atoms from the localized to extended states with a distributed energy gap. We determine the energy band structure of helium films from elasticity. The ground states ofandat, which are possibly a sort of Mott insulator or Mott glass, are identically gapped and compressible.