Ballistic electrons on the hexagonal Fermi surface of PdCoO2

Add to your list(s) Download to your calendar using vCal

• Maja Bachmann, Max-Planck-Institute for Chemical Physics of Solids, Dresden
• Wednesday 21 November 2018, 11:15-12:30
• Mott Seminar Room (531), Cavendish Laboratory, Department of Physics.

If you have a question about this talk, please contact Romy Hall.

Electronic transport in metals is typically diffusive and well described by Ohm’s law. Very small or clean conductors, however, can enter the ballistic regime when the mean-free-path exceeds the size of the sample. This transport regime has been well studied in two-dimensional electron gases, in which the charge carriers are well described by small, circular Fermi surfaces.

In the ultra-pure delafossite metal PdCoO2, however, the electronic system is described by a nearly perfect hexagonal Fermi surface, resulting in three preferred directions of ballistic motion. Exploiting the mean-free-path of over 20µm at low temperatures, we use focused ion beam microstructuring to fabricate ballistic devices from single crystals.

I will present our investigations of constricted channels and transverse electron focusing devices which demonstrate the effects of this peculiar Fermi surface. Ballistic transport simulations further corroborate our experimental results. This is particularly relevant in establishing a complete picture of the exotic ballistic motion in PdCoO2, on top of which strong momentum-conserving scattering processes have been argued to lead to hydrodynamic transport.

This talk is part of the Quantum Matter Seminar series.

This talk is included in these lists:

• All Cavendish Laboratory Seminars
• All Talks (aka the CURE list)
• Centre for Health Leadership and Enterprise
• Featured lists
• ME Seminar
• Mott Seminar Room (531), Cavendish Laboratory, Department of Physics
• Neurons, Fake News, DNA and your iPhone: The Mathematics of Information
• Quantum Matter Seminar
• School of Physical Sciences
• Thin Film Magnetic Talks

Note that ex-directory lists are not shown.