[Landau ITP Seminars] Friday 17.04.2020

[Serge Krashakov]

Уважаемые сотрудники ИТФ,

В пятницу 17 апреля в 11:30 состоится онлайн коллоквиум, на котором 
будет заслушан доклад:

Kamran Behnia (CNRS/ESPCI, PSL Research University, Paris, France)
*Charge and entropy transport in strontium titanate*

The ferroelectric instability in pristine strontium titanate is aborted 
by quantum fluctuations. Therefore, the static electric permittivity 
saturates to an extremely large value at low temperature and the 
effective Bohr radius approaches a micron. In this context, removing a 
tiny fraction of oxygen atoms turns the system to a dilute metal with a 
sharp Fermi surface and a superconducting instability. The focus of this 
talk will be charge and entropy transport by electrons in this dilute 
metal and their general implications.
The temperature dependence of the resistivity of this dilute metal at 
low-temperature implies that electron-electron scattering can generate a 
T-square resistivity even in absence of Umklapp scattering with a single 
Fermi pocket. The magnitude of resistivity at a low temperature would 
imply a mean-free-path too short to be physically plausible. Combined 
with the temperature dependence of the Seebeck coefficient, this implies 
that non-degenerate electrons become heavier with warming. We will see 
that these observations cannot be explained by available polaronic 
theories. There is a whole family of dilute metals emerging from doped 
quantum paraelectrics with similar properties.

Для участия нужно пройти по  ссылке http://bbb2.itp.ac.ru/b/a-o-ytc-2k3
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