Kavli Affiliate: J. C. Seamus Davis
| First 5 Authors: Shuqiu Wang, Kuanysh Zhussupbekov, Joseph P. Carroll, Bin Hu, Xiaolong Liu
| Summary:
Although no known material definitely exhibits intrinsic topological
superconductivity, where a spin-triplet electron pairing potential $Delta(k)$
has odd parity, UTe2 is now the leading candidate. Ideally, the parity of
$Delta(k)$ might be established by using Bogoliubov quasiparticle interference
(QPI) imaging, a recognized technique for $Delta(k)$ determination in complex
superconductors. However, odd-parity superconductors should support a
topological quasiparticle surface band (QSB) on crystal termination surfaces
only for energies within the superconductive energy gap. The QPI should then be
dominated by the QSB electronic structure and only reveal bulk $Delta(k)$
characteristics excursively. Here, by using a superconducting scan-tip to
achieve $sim$ 10 $mu$eV energy resolution QPI for UTe2 studies, we discover
and visualize the in-gap quasiparticle interference patterns of its QSB. QPI
visualization then yields a characteristic sextet $q_{i}:i$ = 1-6 of
interference wavevectors from which we establish QSB dispersions, and their
existence only for energies $|E| leq Delta_{text{max}}$ within the range of
Fermi momenta projected onto the (0-11) crystal surface. Quantitative
evaluation of this sextet $q_{i}$ then demonstrates precisely how the QSB is
projected from the subtending bulk Fermi surface. Finally, a novel theoretical
framework has been developed to predict the QPI signatures of a topological QSB
at this (0-11) surface. Its predictions are demonstrably consistent with the
experimental results if the bulk $Delta(k)$ exhibits time-reversal conserving,
odd-parity, a-axis nodal, B3u symmetry. Ultimately, these new techniques
adumbrate a novel spectroscopic approach to identification of intrinsic
topological superconductors and their superconductive topological surface
states.
| Search Query: ArXiv Query: search_query=au:”J. C. Seamus Davis”&id_list=&start=0&max_results=3