TY - JOUR

T1 - Correlated insulating states in carbon nanotubes controlled by magnetic field

AU - Voliovich, Assaf

AU - Rudner, Mark S.

AU - Oreg, Yuval

AU - Berg, Erez

PY - 2022/12/20

Y1 - 2022/12/20

N2 - We investigate competing insulating phases in nearly metallic zigzag carbon nanotubes, under conditions where an applied magnetic flux approximately closes the single-particle gap in one valley. Recent experiments have shown that an energy gap persists throughout magnetic field sweeps where the single-particle picture predicts that the gap should close and reopen. Using a bosonic low-energy effective theory to describe the interplay between electron-electron interactions, spin-orbit coupling, and magnetic field, we obtain a phase diagram consisting of several competing insulating phases that can form in the vicinity of the single-particle gap closing point. We characterize these phases in terms of spin-resolved charge polarization densities, each of which can independently take one of two possible values consistent with the mirror symmetry of the system, or can take an intermediate value through a spontaneous mirror symmetry breaking transition. In the mirror symmetry breaking phase, adiabatic changes of the orbital magnetic flux drive charge and spin currents along the nanotube. We discuss the relevance of these results to recent and future experiments.

AB - We investigate competing insulating phases in nearly metallic zigzag carbon nanotubes, under conditions where an applied magnetic flux approximately closes the single-particle gap in one valley. Recent experiments have shown that an energy gap persists throughout magnetic field sweeps where the single-particle picture predicts that the gap should close and reopen. Using a bosonic low-energy effective theory to describe the interplay between electron-electron interactions, spin-orbit coupling, and magnetic field, we obtain a phase diagram consisting of several competing insulating phases that can form in the vicinity of the single-particle gap closing point. We characterize these phases in terms of spin-resolved charge polarization densities, each of which can independently take one of two possible values consistent with the mirror symmetry of the system, or can take an intermediate value through a spontaneous mirror symmetry breaking transition. In the mirror symmetry breaking phase, adiabatic changes of the orbital magnetic flux drive charge and spin currents along the nanotube. We discuss the relevance of these results to recent and future experiments.

KW - LUTTINGER-LIQUID

KW - SPIN

KW - POLARIZATION

U2 - 10.1103/PhysRevB.106.235141

DO - 10.1103/PhysRevB.106.235141

M3 - Journal article

VL - 106

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

IS - 23

M1 - 235141

ER -