Noisy defects in a doped Mott insulator

Abstract

Detailed understanding of the role of single dopant atoms in host materials has been crucial for the continuing miniaturization in the semiconductor industry as local charging and trapping of electrons can completely change the behaviour of a device. Similarly, as dopants can turn a Mott insulator into a high temperature superconductor, their electronic behaviour at the atomic scale is of much interest. Due to limited time resolution of conventional scanning tunnelling microscopes, most atomic scale studies in these systems focussed on the time averaged effect of dopants on the electronic structure. Here, by using atomic scale shot-noise measurements in the doped Mott insulator Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+x}$, we visualize sub-nanometer sized objects where remarkable dynamics leads to an enhancement of the tunnelling current noise by at least an order of magnitude. From the position, current and energy dependence we argue that these defects are oxygen dopant atoms that were unaccounted for in previous scanning probe studies, whose local environment leads to charge dynamics that strongly affect the tunnelling mechanism. The unconventional behaviour of these dopants opens up the possibility to dynamically control doping at the atomic scale, enabling the direct visualization of the effect of local charging on e.g. high T${}_{\text{c}}$ superconductivity.

12 pages, 4 figures, Supplementary Information included as ancillary file

References in corpus (8)

• Metallic supercurrent field-effect transistor
• Super-poissonian noise, negative differential conductance, and relaxation effects in transport through molecules, quantum dots and nanotubes
• Interpretation of scanning tunneling quasiparticle interference and impurity states in cuprates
• Correlating off-stoichiometric doping with nanoscale electronic disorder and quasiparticle interference pattern in high-$T_c$ superconductor Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$
• Amplifier for scanning tunneling microscopy at MHz frequencies
• Atomic scale shot-noise using broadband scanning tunnelling microscopy
• Electron Bunching in Transport Through Quantum Dots in High Magnetic Field
• Nanoscale interplay of strain and doping in a high-temperature superconductor

Cited by in corpus (10)

• Imaging doubled shot noise in a Josephson scanning tunneling microscope
• Dynamical Coulomb Blockade as a Local Probe for Quantum Transport
• Spatially correlated incommensurate lattice modulations in an atomically thin high-temperature Bi_{2.1}Sr_{1.9}CaCu_{2.0}O_{8+δ} superconductors
• Atomic manipulation of the gap in Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+x}$
• Design and performance of an ultrahigh vacuum spectroscopic-imaging scanning tunneling microscope with a hybrid vibration isolation system
• Scanning Tunneling Shot Noise Spectroscopy in Kondo Systems
• Extracting the Transport Channel Transmissions in Scanning Tunneling Microscopy using the Superconducting Excess Current
• Influence of nano-hole defects and their geometric arrangements on the superfluid density in atomically thin single crystals of indium superconductor
• Shot-noise and differential conductance as signatures of putative topological superconductivity in FeSe${}_{0.45}$Te${}_{0.55}$
• Magnon bands in twisted bilayer honeycomb quantum magnets