Interplay of Superconductivity, Quantum Oscillations, and Charge Density Wave in YBa2Cu3O6+x
Lead Research Organisation:
University of Cambridge
Department Name: Physics
Abstract
The discovery of copper-oxide high temperature superconductors in 1986 triggered an explosion of experimental and theoretical research into both improving our understanding of their unconventional properties, and promises of future technological innovations. YBa2Cu3O6+x is one of the most studied of all cuprates and remains a fertile material for exploring various exotic quantum phases including, but not exhaustive to, superconductivity.
After three decades, however, many questions regarding these strongly correlated materials remain unresolved. A complete understanding of the transport and Fermi surface properties of the underdoped cuprates remain unresolved, as well as the extent of the superconducting vortex liquid as a function of temperature and magnetic field. Quantum oscillation techniques allow us to experimentally probe and map out the Fermi surface by exploiting the constrained motion of the electrons near the Fermi energy in a magnetic field. The scope of the PhD project is to perform transport, thermodynamic, and quantum oscillation measurements in underdoped YBa2Cu3O6+x in order to resolve the extent of the superconducting vortex liquid state, its interplay with quantum oscillations, and potentially the charge density wave as a function of high magnetic fields and temperatures.
After three decades, however, many questions regarding these strongly correlated materials remain unresolved. A complete understanding of the transport and Fermi surface properties of the underdoped cuprates remain unresolved, as well as the extent of the superconducting vortex liquid as a function of temperature and magnetic field. Quantum oscillation techniques allow us to experimentally probe and map out the Fermi surface by exploiting the constrained motion of the electrons near the Fermi energy in a magnetic field. The scope of the PhD project is to perform transport, thermodynamic, and quantum oscillation measurements in underdoped YBa2Cu3O6+x in order to resolve the extent of the superconducting vortex liquid state, its interplay with quantum oscillations, and potentially the charge density wave as a function of high magnetic fields and temperatures.
Organisations
People |
ORCID iD |
| Suchitra Sebastian (Primary Supervisor) | |
| Alexander Davies (Student) |
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509620/1 | 01/10/2016 | 30/09/2022 | |||
| 1805236 | Studentship | EP/N509620/1 | 01/10/2016 | 31/03/2020 | Alexander Davies |
| Description | I have been able to grow single-crystal samples of high-temperature superconducting cuprates using a self-flux method. These samples have been subsequently used in a series of experiments in the UK and abroad utilising extremely powerful magnetic fields. Magnetic fields are able to suppress superconductivity in these materials and allow exploration of the otherwise hidden low-temperature physics. Along with my colleagues, I have measured the electrical resistivity and Hall effect in these samples as a function of temperature, magnetic field, and oxygen doping. I have discovered (i) monitoring of the field-dependence of these samples as a function of applied current revealed that the superconducting state persists well above the maximum feasible magnetic fields available at present and hence the superconducting state is more robust than previously stated. (ii) From the Hall effect, we can determine the total carrier density inside our materials which carry the electrical current. By monitoring this as a function of the oxygen doping we have revealed that the material shows properties not consistent with a simple Fermi liquid and indirectly it reveals more information concerning how the Fermi surface develops across the superconducting state from underdoped to overdoped. |
| Exploitation Route | Our work is unpublished at present. This work will be a huge extensive data-set of the electrical transport properties of this family of materials. At present, no one has measured the electrical resistivity and Hall coefficient over such as fine detailed range of dopings across the superconducting region in the materials phase diagram. It will likely leads to it being published in a high impact journal once completed, because it will be beneficial to the community and be of interest to theorists interested in modelling the pseudogap or strange metal phases. |
| Sectors | Electronics,Energy,Manufacturing, including Industrial Biotechology |