Terahertz magneto-nanoscopy of encapsulated monolayer graphene

R Richard H. J. Kim (Ames National Laboratory, US Department of Energy 1 , Ames, Iowa 50011,) S Sunwoong Yang (Division of Science Education, Kangwon National University 2 , Chuncheon 24341,) T Taehoon Kim (Silklab, Department of Biomedical Engineering, Tufts University) S Samuel J. Haeuser (Department of Physics and Astronomy, Iowa State University 2 , Ames, Iowa 50011,) J Joong-Mok Park (Ames National Laboratory, US Department of Energy 1 , Ames, Iowa 50011,) R Randall K. Chan (Department of Physics and Astronomy, Iowa State University 2 , Ames, Iowa 50011,) T Thomas Koschny (Ames National Laboratory, US Department of Energy 1 , Ames, Iowa 50011,) Y Young-Mi Bahk (Department of Physics, Incheon National University 3 , Incheon 22012,) S Sung Ju Hong (Division of Science Education, Kangwon National University 2 , Chuncheon 24341,) J Jigang Wang (Artemisinin Research Center and Institute of Chinese Materia Medica)

Abstract

This study investigates the nanoscale conductivity of encapsulated monolayer graphene at temperatures down to 5 K and magnetic fields of up to 1 T. We use the scattering-type scanning near-field optical microscopy technique to probe magnetic-field-dependent responses from graphene close to charge neutrality in the terahertz spectral region. We observe the near-perfect high-q reflector behavior of graphene but with subtle changes by the presence of magnetic fields. Measurements align with calculations of the magneto-optical conductivity and the near-field spectroscopic contrast that describes the field-tunable cyclotron resonance of Dirac fermions. Our result provides an initial step toward understanding temperature and magnetic field effects on nanoscale terahertz transport in two-dimensional quantum materials.

Article Details

Volume / Issue Vol. 139, Issue 16
Published April 28, 2026
ISSN 0021-8979
Publisher American Institute of Physics

Journal Info

Journal of Applied Physics

American Institute of Physics

ISSN: 0021-8979 Physical Sciences

Authors (10)

R

Richard H. J. Kim

Ames National Laboratory, US Department of Energy 1 , Ames, Iowa 50011,

S

Sunwoong Yang

Division of Science Education, Kangwon National University 2 , Chuncheon 24341,

T

Taehoon Kim

Silklab, Department of Biomedical Engineering, Tufts University

S

Samuel J. Haeuser

Department of Physics and Astronomy, Iowa State University 2 , Ames, Iowa 50011,

J

Joong-Mok Park

Ames National Laboratory, US Department of Energy 1 , Ames, Iowa 50011,

R

Randall K. Chan

Department of Physics and Astronomy, Iowa State University 2 , Ames, Iowa 50011,

T

Thomas Koschny

Ames National Laboratory, US Department of Energy 1 , Ames, Iowa 50011,

Y

Young-Mi Bahk

Department of Physics, Incheon National University 3 , Incheon 22012,

S

Sung Ju Hong

Division of Science Education, Kangwon National University 2 , Chuncheon 24341,

J

Jigang Wang

Artemisinin Research Center and Institute of Chinese Materia Medica