Effect of hydrostatic pressure on the fragmented conduction band structure of dilute Ga(AsN) alloys

Abstract

We show that the combined use of magneto-tunneling spectroscopy and hydrostatic pressure $P$ provides a powerful means of probing and strongly modifying the fragmented conduction band structure of dilute $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}y}{\mathrm{N}}_{y}$ quantum well layers. We demonstrate the strong effect of pressure on the $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}y}{\mathrm{N}}_{y}$ states over a wide range of energies and $k$ vectors not accessible in previous optical investigations of interband transitions around $k=0$. Also, we report a large pressure coefficient for the effective mass, $m$, of the conduction electrons, $\ensuremath{\partial}m∕\ensuremath{\partial}P\ensuremath{\approx}3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}{m}_{e}\phantom{\rule{0.3em}{0ex}}{\mathrm{kbar}}^{\ensuremath{-}1}$, nearly an order of magnitude larger than that found in GaAs ($\ensuremath{\partial}m∕\ensuremath{\partial}P=4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}{m}_{e}\phantom{\rule{0.3em}{0ex}}{\mathrm{kbar}}^{\ensuremath{-}1}$, where ${m}_{e}$ is the electron mass in vacuum).