利用超高斯光模拟方势垒

Theoretical simulations of the square potential barrier with a super-Gaussian beam

方势垒是一个研究量子力学中隧穿问题的理想模型.提出了利用具有大蓝失谐的超高斯光和原子相互作用的偶极势能和超高斯光和电子的有质动力势能模拟方势垒.通过比较超高斯势垒对入射平面波散射的数值解和方势垒对物质波散射的解析解,发现当超高斯光场阶数大于20时能够有效地模拟方势垒对物质波的散射问题.进一步研究了物质波入射到双超高斯势垒的共振隧穿现象.研究结果为在实验上使用超高斯光束模拟方势垒量子隧穿现象提供了理论基础.

The square potential barrier is an ideal model for investigation of quantum tunneling. We simulate the square potential barrier by using the dipole potential for the interaction between an atom and a blue-detuned far-off-resonant super-Gaussian beam, as well as the ponderomotive potential for the interaction between an electron and a super-Gaussian beam. A comparison between the numerical results for scattering by the super-Gaussian potential barrier and the analytical results for scattering by a square potential barrier shows that a super-Gaussian beam with an order exceeding 20 could simulate a square potential barrier accurately. We also show that two super-Gaussian beams could be used to study the resonant quantum tunneling effect. In summary, our results could be applied to an experimental investigation of quantum tunneling through a square potential barrier.