STM Studies of the Electronic Structure of Vortex Cores in <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>Bi</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow><mrow><msub><mrow><mi>Sr</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow><mrow><msub><mrow><mi>CaCu</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow><mrow><msub><mrow><mi>O</mi></mrow><mrow><mn>8</mn><mo>+</mo><mi>δ</mi></mrow></msub></mrow></math></span>

S. H. Pan; E. W. Hudson; A. K. Gupta; K.-W. Ng; H. Eisaki; S. Uchida; J. C. Davis

doi:10.1103/PhysRevLett.85.1536

STM Studies of the Electronic Structure of Vortex Cores in ${Bi}_{2} {Sr}_{2} {CaCu}_{2} O_{8 + δ}$

S. H. Pan, E. W. Hudson, A. K. Gupta, K.-W. Ng, H. Eisaki, S. Uchida, and J. C. Davis

Phys. Rev. Lett. 85, 1536 – Published 14 August 2000

Abstract

We report on low temperature scanning tunneling microscopy (STM) studies of the electronic structure of vortex cores in $Bi_{2} Sr_{2} CaCu_{2} O_{8 + δ}$ . At the vortex core center, an enhanced density of states is observed at energies near $Ω = \pm 7 meV$ . Spectroscopic imaging at these energies reveals an exponential decay of these “core states” with a decay length of $22 \pm 3 Å$ . The fourfold symmetry sometimes predicted for $d$ -wave vortices is not seen in spectroscopic vortex images. A locally nodeless order parameter induced by the magnetic field may be consistent with these measurements.

Received 12 May 2000

DOI:https://doi.org/10.1103/PhysRevLett.85.1536

Authors & Affiliations

S. H. Pan^1,*, E. W. Hudson^1,†, A. K. Gupta², K.-W. Ng², H. Eisaki^3,‡, S. Uchida³, and J. C. Davis¹

¹Department of Physics, University of California, Berkeley, California 94720-7300
²Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055
³Department of Superconductivity, Tokyo University, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan

^*Present address: Department of Physics, Boston University, Boston, Massachusetts 02215.
^†Present address: Electron Physics Group, National Institute of Standards and Technology, Gaithersburg, Maryland 20899.
^‡Present address: Department of Applied Physics, Stanford University, Stanford, California 94205-4060.