@article{le_anomalous_2024,

title = {Anomalous induced density of supercritical Coulomb impurities in graphene under strong magnetic fields},

author = {Hoang-Anh Le and S. -R. Eric Yang},

url = {https://link.aps.org/doi/10.1103/PhysRevB.110.085156},

doi = {10.1103/PhysRevB.110.085156},

issn = {2469-9950, 2469-9969},

year  = {2024},

date = {2024-08-01},

urldate = {2024-08-01},

journal = {Physical Review B},

volume = {110},

number = {8},

pages = {085156},

abstract = {The Coulomb impurity problem of graphene, in the absence of a magnetic field, displays discrete scale invariance. Applying a magnetic field introduces a new magnetic length scale ℓ and breaks discrete scale invariance. Moreover, a magnetic field is a singular perturbation as it turns complex energies into real energies. Nonetheless, the Coulomb potential must be regularized with a length 𝑅 at short distances for supercritical impurities. We investigate the structure of the induced density of a filled Landau impurity band in the supercritical regime. The coupling between Landau level states by the impurity potential is nontrivial and can lead to several anomalous effects. First, we find that the peak in the induced density can be located away from the center of the impurity, depending on the characteristics of the Landau impurity bands. Second, the impurity charge is screened, despite the Landau impurity band being filled. Third, anticrossing impurity states lead to additional impurity cyclotron resonances.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Le2024,

title = {Phase diagram and crossover phases of topologically ordered graphene zigzag nanoribbons: role of localization effects},

author = {Hoang-Anh Le and In-Hwan Lee and Young Heon Kim and S-R Eric Yang},

doi = {10.1088/1361-648x/ad38f9},

issn = {1361-648X},

year  = {2024},

date = {2024-07-03},

urldate = {2024-07-03},

journal = {J. Phys.: Condens. Matter},

volume = {36},

number = {26},

publisher = {IOP Publishing},

abstract = {We computed the phase diagram of zigzag graphene nanoribbons as a function of on-site repulsion, doping, and disorder strength. The topologically ordered phase undergoes topological phase transitions into crossover phases, which are new disordered phases with non-universal topological entanglement entropy that exhibits significant variance. We explored the nature of non-local correlations in both the topologically ordered and crossover phases. In the presence of localization effects, strong on-site repulsion and/or doping weaken non-local correlations between the opposite zigzag edges of the topologically ordered phase. In one of the crossover phases, both e-/2 solitonic fractional charges and spin-charge separation were absent; however, charge-transfer correlations between the zigzag edges were possible. Another crossover phase contains solitonic e-/2 fractional charges but lacks charge transfer correlations. We also observed properties of non-topological, strongly disordered, and strongly repulsive phases. Each phase on the phase diagram exhibits a different zigzag-edge structure. Additionally, we investigated the tunneling of solitonic fractional charges under an applied voltage between the zigzag edges of undoped topologically ordered zigzag ribbons, and found that it may lead to a zero-bias tunneling anomaly.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}