Wei Li

Chinese Academy of Sciences | CAS · Key Laboratory of Materials Physics,

In this work, we study the resonant tunneling (RT) of electrons and H atoms in double-barrier (DB) systems. Our numerical calculations directly verify the correspondence between the resonant tunneling energies and the energy levels of quasi-bound states (QBS) within the double barriers. Based on this, in-depth analyses are carried out on the modula...

Understanding the correlation effects in unconventional topological materials, in which the fermion excitations take unusual dispersion, is an important topic in recent condensed matter physics. We study the influence of short-range four-fermion interactions on three-dimensional semi-Dirac semimetal with an unusual fermion dispersion that is linear...

Proton transfer plays a key role in the applications of advanced energy materials as well as in the functionalities of biological systems. In this work, based on the transfer matrix method, we study the quantum effects of proton transfer in a series of one-dimensional (1D) model potentials and numerically calculate the quantum probability of transf...

Taking into account the interplay between the disorder and Coulomb interactions, the phase diagram of three-dimensional anisotropic-Weyl semimetal is studied by renormalization group theory. It is well established that the weak disorder is irrelevant in 3D anisotropic-Weyl semimetal, while the strong disorder makes sense which drives a quantum phas...

Understanding the correlation effects in unconventional topological materials, in which the fermion excitations take unusual dispersion, is an important topic in recent condensed matter physics. We study the influence of short-range four-fermion interactions on three-dimensional semi-Dirac semimetal with an unusual fermion dispersion, that is linea...

Influence of short-range four-fermion interactions on quadratic and cubic nodal-line fermion systems is studied by renormalization group theory. It is found that arbitrarily weak four-fermion interaction could drive quadratic or cubic nodal-line fermion system to a new phase. According to the initial conditions and value of fermion flavor, the syst...

Influence of short-range four-fermion interactions on quadratic and cubic nodal line fermion systems is studied by renormalization group theory. It is found that arbitrarily weak four-fermion interaction could drive quadratic or cubic nodal line fermion system to a new phase. According to the initial conditions and value of fermion flavor, the syst...

β-PtO2 is a useful transition metal dioxide, but its fundamental thermodynamic and elastic properties remain unexplored. Using first-principles calculations, we systematically studied the structure, phonon, thermodynamic and elastic properties of β-PtO2. The lattice dynamics and structural stability of β-PtO2 under pressure were studied using the p...

Taking into account the interplay between the disorder and Coulomb interaction, the phase diagram of three-dimensional anisotropic Weyl semimetal is studied by renormalization group theory. Weak disorder is irrelevant in anisotropic Weyl semimetal, while the disorder becomes relevant and drives a quantum phase transition from semimetal to compressi...

We investigate the vacancy effects on quasiparticle band structure of graphene near the Dirac point. It is found that each Dirac nodal point splits into two new nodal points due to the coherent scattering among vacancies. The splitting energy between the two nodal points is proportional to the square root of vacancy concentration. In addition, an e...

The three-dimensional non-compact QED is known to exhibit weak confinement when fermions acquire a finite mass via the mechanism of dynamical chiral symmetry breaking. In this paper, we study the effect of fermion damping caused by elastic scattering on the classical potential between fermions. By calculating the vacuum polarization function that i...

The strong Coulomb interaction between massless Dirac fermions can drive a semimetal-insulator transition in single-layer graphene by dynamically generating an excitonic fermion gap. There is a critical interaction strength $\lambda_c$ that separates the semimetal phase from the insulator phase. We calculate the specific heat and susceptibility of...

We study the effects of finite chemical potential and impurity scattering on dynamical fermion mass generation in (2+1)-dimensional quantum electrodynamics. In any realistic systems, these effects usually can not be neglected. The longitudinal component of gauge field develops a finite static length produced by chemical potential and impurity scatt...

We study chiral phase transition and confinement of matter fields in (2+1)-dimensional U(1) gauge theory of massless Dirac fermions and scalar bosons. The vanishing scalar boson mass, r=0, defines a quantum critical point between the Higgs phase and the Coulomb phase. We consider only the critical point r=0 and the Coulomb phase with r>0. The Dirac...

We study chiral phase transition and confinement of matter fields in (2+1)-dimensional U(1) gauge theory of massless Dirac fermions and scalar bosons. The vanishing scalar boson mass, $r=0$, defines a quantum critical point between the Higgs phase and the Coulomb phase. We consider only the critical point $r=0$ and the Coulomb phase with $r > 0$. T...

We study dynamical chiral symmetry breaking (DCSB), confinement, and disorder effects in (2+1)-dimensional quantum electrodynamics (QED) of massless fermion ψ and scalar boson ϕ. It is found that gauge symmetry breaking (GSB) induced by nonzero ⟨ϕ⟩ rapidly suppresses the occurrence of DCSB, and certain disorders tend to enhance it. While DCSB leads...

The strong long-range Coulomb interaction between massless Dirac fermions in graphene can drive a semimetal-insulator transition. We show that this transition is strongly suppressed when the Coulomb interaction is screened by such effects as disorder, thermal fluctuation, doping, and finite volume. It is completely suppressed once the screening fac...