![In a certain two-dimensional lattice, the energy dispersion of the electrons is](https://www.gkseries.com/blog/wp-content/uploads/2023/09/In-a-certain-two-dimensional-lattice-the-energy-dispersion-of-the-electrons-is.jpg)
Q. In a certain two-dimensional lattice, the energy dispersion of the electrons is
![](https://www.gkseries.com/blog/wp-content/uploads/2023/09/Screenshot-801.png)
where ๐โโย = (๐๐ฅ , ๐๐ฆ) denotes the wave vector, ๐ is the lattice constant and ๐ก is a constant in units of eV. In this lattice the effective mass tensor ๐๐๐ of electrons calculated at the center of the Brillouin zone has the form
![](https://www.gkseries.com/blog/wp-content/uploads/2023/09/Screenshot-802.png)
The value of ๐ผ (rounded off to three decimal places) is ย ย ย ย ย ย ย ย ย ย ย
Ans: 0.33