Quasi-energy spectra of a charged particle in planar honeycomb lattices

Zhang, Wei; Zhang, Ping; Duan, Suqing; Zhao, Xian-Geng

doi:10.1088/1367-2630/11/6/063032

Cited by 14 publications

(24 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the F 0 approximation, k,σ,l=0 = ± 0,F 0 , see Eq. (19), and the density of states can be calculated analytically yielding…”

Section: Single-particle Properties Of the Hamiltonian Derived Fromentioning

confidence: 99%

“…14 Experimentally it has been found that a circularly polarized ac field induces a dynamic Hall effect in graphene. 15 Several studies have been devoted to the theoretical analysis of the quasienergy spectrum of graphene and graphene dots under ac fields, [16][17][18][19] and the optical properties of graphene have been studied by calculating the optical conductivity. 20 One of the earliest and yet most important findings in all these studies is that a circularly polarized field induces a band gap at the Dirac point, along with dynamical gaps at other momenta, all of which are tunable by the field intensity.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dynamical polarizability of graphene irradiated by circularly polarized ac electric fields

2012

View full text Add to dashboard Cite

We examine the low-energy physics of graphene in the presence of a circularly polarized electric field in the terahertz regime. Specifically, we derive a general expression for the dynamical polarizability of graphene irradiated by an ac electric field. Several approximations are developed that allow one to develop a semianalytical theory for the weak field regime. The ac field changes qualitatively the single and many electron excitations of graphene: undoped samples may exhibit collective excitations (in contrast to the equilibrium situation), and the properties of the excitations in doped graphene are strongly influenced by the ac field. We also show that the intensity of the external field is the critical control parameter for the stability of these excitations.

show abstract

“…In the F 0 approximation, k,σ,l=0 = ± 0,F 0 , see Eq. (19), and the density of states can be calculated analytically yielding…”

Section: Single-particle Properties Of the Hamiltonian Derived Fromentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Dynamical polarizability of graphene irradiated by circularly polarized ac electric fields

2012

View full text Add to dashboard Cite

show abstract

“…The polarization is essential for renormalization of those hopping integrals because the applied field should uniformly disturb the electronic system. Effects by electric field with other polarizations, e.g., linear polarization, on a related honeycomb system are discussed in [19]. The driving laser field with a fixed ω can be expressed as where corresponds to left (right) circular polarization.…”

Section: Adiabatic Photo-steering Theory In Topological Insulatorsmentioning

confidence: 99%

Adiabatic photo-steering theory in topological insulators

Inoue

2014

Science and Technology of Advanced Materials

View full text Add to dashboard Cite

Feasible external control of material properties is a crucial issue in condensed matter physics. A new approach to achieving this aim, named adiabatic photo-steering, is reviewed. The core principle of this scheme is that several material constants are effectively turned into externally tunable variables by irradiation of monochromatic laser light. Two-dimensional topological insulators are selected as the optimal systems that exhibit a prominent change in their properties following the application of this method. Two specific examples of photo-steered quantum phenomena, which reflect topological aspects of the electronic systems at hand, are presented. One is the integer quantum Hall effect described by the Haldane model, and the other is the quantum spin Hall effect described by the Kane–Mele model. The topological quantities associated with these phenomena are the conventional Chern number and spin Chern number, respectively. A recent interesting idea, time-reversal symmetry breaking via a temporary periodic external stimulation, is also discussed.

show abstract

“…Solution profiles for the soliton backgrounds were explored analytically and numerically in a companion paper [25]. We note that similar solitons appear in nonlinear optics [26,27], in graphene [28][29][30][31][32][33], and in various other fields of physics [34][35][36][37][38][39][40][41][42][43][44]. Figure 1 provides a schematic of our setup depicting a soliton and its fluctuations in the quasi-one-dimensional (quasi-1D) reduction of the honeycomb lattice to the armchair nanoribbon.…”

Section: Introductionmentioning

confidence: 99%

Spin-Polarized Hot Electron Injection into Two-Dimensional Electron Gas by Magnetic Tunnel Transistor

Tae

Eom

Song

et al. 2007

jjap

View full text Add to dashboard Cite

The nonlinear Dirac equation for Bose-Einstein condensates (BECs) in honeycomb optical lattices gives rise to relativistic multi-component bright and dark soliton solutions. Using the relativistic linear stability equations, the relativistic generalization of the Boguliubov-de Gennes equations, we compute soliton lifetimes against quantum fluctuations and classify the different excitation types. For a BEC of Rb 87 atoms, we find that our soliton solutions are stable on time scales relevant to experiments. Excitations in the bulk region far from the core of a soliton and bound states in the core are classified as either spin waves or as a Nambu-Goldstone mode. Thus, solitons are topologically distinct pseudospin-1 2 domain walls between polarized regions of S 1 2 z = ± . Numerical analysis in the presence of a harmonic trap potential reveals a discrete spectrum reflecting the number of bright soliton peaks or dark soliton notches in the condensate background. For each quantized mode the chemical potential versus nonlinearity exhibits two distinct power law regimes corresponding to the free-particle (weakly nonlinear) and soliton (strongly nonlinear) limits.

show abstract

Quasi-energy spectra of a charged particle in planar honeycomb lattices

Cited by 14 publications

References 38 publications

Dynamical polarizability of graphene irradiated by circularly polarized ac electric fields

Dynamical polarizability of graphene irradiated by circularly polarized ac electric fields

Adiabatic photo-steering theory in topological insulators

Spin-Polarized Hot Electron Injection into Two-Dimensional Electron Gas by Magnetic Tunnel Transistor

Contact Info

Product

Resources

About