Mott gap collapse in lightly hole-doped Sr2-xKxIrO4

J N Nelson; C T Parzyck; B D Faeth; J K Kawasaki; D G Schlom; K M Shen

doi:10.1038/s41467-020-16425-z

Mott gap collapse in lightly hole-doped Sr_2-xK_xIrO₄

Nat Commun. 2020 May 22;11(1):2597. doi: 10.1038/s41467-020-16425-z.

Authors

J N Nelson¹, C T Parzyck¹, B D Faeth¹, J K Kawasaki^{1

2

3

4}, D G Schlom^{2

3}, K M Shen^{5

6}

Affiliations

¹ Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York, 14853, USA.
² Department of Materials Science and Engineering, Cornell University, Ithaca, New York, 14853, USA.
³ Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York, 14853, USA.
⁴ Department of Materials Science and Engineering, University of Wisconsin, Madison, Wisconsin, 53706, USA.
⁵ Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York, 14853, USA. [email protected].
⁶ Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York, 14853, USA. [email protected].

Abstract

The evolution of Sr₂IrO₄ upon carrier doping has been a subject of intense interest, due to its similarities to the parent cuprates, yet the intrinsic behaviour of Sr₂IrO₄ upon hole doping remains enigmatic. Here, we synthesize and investigate hole-doped Sr_2-xK_xIrO₄ utilizing a combination of reactive oxide molecular-beam epitaxy, substitutional diffusion and in-situ angle-resolved photoemission spectroscopy. Upon hole doping, we observe the formation of a coherent, two-band Fermi surface, consisting of both hole pockets centred at (π, 0) and electron pockets centred at (π/2, π/2). In particular, the strong similarities between the Fermi surface topology and quasiparticle band structure of hole- and electron-doped Sr₂IrO₄ are striking given the different internal structure of doped electrons versus holes.