The ballistic transmission of the Dirac ultrarelativistic quasielectrons in graphene structures with the rectangular potential barrier is considered, and both the single and the double-barrier structures are analyzed. Within the framework of the continuum model, the transmission coefficient of quasielectrons T is calculated depending on the parameters of the problem. It is believed that there is an electrostatic barrier, as well as the Fermi velocity barrier, due to the fact that this quantity may acquire different values in the barrier and out-of-barrier regions (υ_F2 and υ_F1, respectively) of the considered structures. It is shown that the effect of the supertunneling manifests itself in these structures which consists in the fact that under certain conditions the transmission through the structure is perfect (transmission rates T = 1) for the arbitrary angle of incidence of quasielectrons on the barrier. In the case of different values of the Fermi velocities in the barrier and out-of-barrier regions (the parameter β = υ_F2/υ_F1, which characterizes the velocity barrier, is not equal to unity), the supertunneling is observed for a certain ratio between the energy E and the barrier height U and significantly depends on β. The expression is given that determines the specified conditions for the supertunneling. In the case of equal velocities (β = 1), the supertunneling effect is observed for the quasielectron energy value E equal to half the height of the electrostatic barrier U. The analysis of the dependence of the transmission on the problem parameters is also provided.

中文翻译：

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石墨烯中的超隧道效应

考虑了狄拉克超相对论准电子在具有矩形势垒的石墨烯结构中的弹道传输，并分析了单势垒和双势垒结构。在连续模型的框架内，根据问题的参数计算准电子的透射系数T。据信，有静电屏障，以及费米速度屏障，由于这样的事实，这个量可以在阻挡取得不同的值和乱势垒区（υ _{˚F 2}和υ _{˚F 1}）。结果表明，超隧道效应本身就体现在这些结构中，这是因为在一定条件下， 对于准电子在势垒上的任意入射角，通过该结构的传输都是完美的（传输速率T = 1）。在屏障和外的势垒区的费米速度的不同值的情况下（所述参数β=υ _{˚F 2} /υ _{˚F 1}，表征速度屏障，不等于统一），则supertunneling观察对于能量E和势垒高度U之间的一定比例并明显取决于β。给出了确定超级隧道的指定条件的表达式。在等速（β= 1）的情况下，对于准电子能量值E等于静电势垒U高度的一半，观察到超隧道效应。还提供了传输对问题参数的依赖性分析。