The recently computed result for charge density penetrating into the barrier region of a capped (5,5) carbon nanotube in zero applied field is compared with the analysis of Kohn and Mattsson for a narrow region near the Fermi equipotential. The decrease of charge density with distance into the barrier is found to be faster for the computed result, possibly resulting from a limitation in the density functional used.

中文翻译：

---

关于场发射体表面附近的电荷密度和电势

将最近计算的电荷密度在零外加场中渗入封端 (5,5) 碳纳米管的势垒区的结果与 Kohn 和 Mattsson 对费米等势附近狭窄区域的分析进行了比较。对于计算结果，发现电荷密度随着进入势垒的距离而降低得更快，这可能是由于所使用的密度泛函的限制所致。