A top-down model for layered holographic strange metals
Typ
Examensarbete för masterexamen
Program
Physics and astronomy (MPPAS), MSc
Publicerad
2021
Författare
Lexell, Olle
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
The AdS/CFT correspondence is a potentially powerful tool in describing condensed matter systems
for which our current theoretical understanding is lacking. This is because it can be used to map a
strongly coupled field theory to a weakly coupled gravitational theory. In this thesis I describe some
aspects of the AdS/CFT correspondence and look at a top-down model. This model is built upon a
large number of D3 and D5 branes with a D7 probe brane. The goal is to see whether this model
can be used to describe aspects of the strange metal phase that is found in layered high-temperature
superconductors. Starting from a weakly coupled string theory setting I derive the temperaturedependence
of a DC current in different regimes, as well as dispersion relations for electromagnetic
fluctuations. There is a possibility of obtaining resistivity that matches the linear in T dependence
for the resistivity in strange metals. This is done by adjusting the number of D5 branes depending on
the temperature and the charge density, which is obtained holographically. With a particular choice
of boundary conditions, plasmonic dispersion relations are found, as required. This is the first layered
top-down model with this behaviour for the current available in its parameter-space. While it has
not produced correct predictions without an adjustment of the parameter-space, the freedoms granted
from the said parameter-space makes it possible that this model could describe other layered systems
that lacks quasi-particles, and not just strange metals.
Beskrivning
Ämne/nyckelord
AdS/CFT , Top-down , D3-D5 geometry , D7 probe brane , holographic strange metals , holographic plasmons , mixed boundary conditions , resistivity linear in temperature