A Theoretical Study On The Influence Of Pseudomagnetic Field On The Electroexcitation State Of Strained Graphene Surface

Since 2004,Novoselov has successfully prepared graphene,due to its unique structure and physical properties,it has caused a climax of research worldwide.Graphene has a perfect lattice structure,small size and quantum size effect,which determines its many peculiar properties,such as extremely fast carrier mobility,high strength,and good thermal properties.At present,it has been regarded as a substitute for silicon,used to make supercomputers,space cables,and is the most promising new material.Graphene has broad application prospects in industry and electronics industry.Therefore,the research and development of graphene has important meanings in future life.This paper mainly uses the linearized quantum hydrodynamics(Quantum Hydrodynamics QHD)theory to study the interaction between charged particles and the strained graphene plane.In the second chapter,the linearized quantum hydrodynamic model is used to study the interaction between incident particle and double-layered graphene in the presence of an insulating medium.The results show that the dielectric constant has a important effect on the electron gas density,the spatial distribution of the induced potential,the stopping force and image force on the incident particle.As the dielectric constant increases,the perturbed electron gas density and the wavelength of the induced potential oscillation both increase,while the amplitude of the oscillation decreases.A clear double-peak structure occurred to the stopping force acting on the incident particles which similar to that of vacuum.As the dielectric constant increases,the stopping force decreases in value and both peaks move to the low-speed region.For the image force,there is also a double-peak structure,which is different from the stopping force.With the increase of the dielectric constant,the image force decreases numerically inside the low-speed region and the peak moves toward the low-speed direction.In the high-speed area,the value increases.In the third chapter,the effects of pseudomagnetic field on electrostatic excitation of charged particles moving above and between double-layer strained graphene sheets were studied.The results show that the pseudomagnetic field has a certain effect on the electron gas density and induced potential in two strained graphene sheets,as well as the stopping force and image force on the incident particle.In the plane of graphene far away from the incident particle the electron gas density distribution has a bimodal structure symmetrical with respect to the particle position.As the intensity of the pseudomagnetic field increases,the double peak structure gradually disappears.When the particle move at a higher speed,the perturbed electron gas density and induced potential appear asymmetric wake,as the velocity of the incident particle increases,the oscillation wavelength becomes longer,for a given particle velocity,as the intensity of the pseudomagnetic field increases,the wavelength gradually becomes shorter.In addition,there is an obvious double-peak structure of the stopping force versus speed curve.In the low-speed region,the peak is larger and narrower,but it is the opposite in the high-speed region.For the image force,however,the double-peak structure is not obvious as it of stopping force.When the incident particles move between the two strained graphene sheets,at a low speed,the bimodal structure does not appear to the electron gas density in both graphene planes.There is no double peak structure for the stopping force and image force.As the distance between the incident particle and a graphene sheets get closer,the stopping force and image force are also getting larger and larger.In the fourth chapter,the electrostatic excitation of the incident proton interacting with the double-layered strained graphene sheets filled with insulating medium was studied.The calculation results show that at low velocities,the electron gas density in the plane farther away from the incident particles has an obvious double-peak structure.As the dielectric constant increases,the double-peak structure becomes more obvious,and the plasma excitation speed threshold decreases.In addition,the change in dielectric constant has different effects on the perturbed electron density of the main peak region in the two planes.For the curve of stopping force changes with speed,the near-degraded small peak-to-peak value at low speed is much smaller than the peak value at a slightly higher speed.If given a pseudomagnetic field,as the dielectric constant increases,both peaks move to the low-speed region,and the speed threshold becomes smaller.With respect to the image force,as the dielectric constant increases,the peak also moves to the low-velocity region.In the low-velocity region,the dielectric constant has little effect on the image force on the incident patticle,but in the high-velocity region,the effect is very large.In the fifth chapter,the overall research content is summarized.