Resistively detected high-order magnetoplasmons in a high-quality two-dimensional electron gas

We report on high-order magnetoplasmon resonances detected in photoresistance in high-mobility GaAs quantum wells. These resonances manifest themselves as a series of photoresistance extrema in the regime of Shubnikov–de Haas oscillations. Extending to orders as high as 25, the extrema exhibit alternating strength, being less (more) pronounced at even- (odd)-order magnetoplasmon modes. This experimental technique provides a sensitive and elegant means to detect and investigate multiple magnetoplasmon modes and could be applied to other systems.

Figure 1

(a) [(b)] $\rho \left(B\right)$ measured in sample A [B] at $f=378$ [333] GHz and $T\approx 0.38$ [0.31] K. SdHO minima in (a) are marked by filling factor $\nu =8$, 10, 12, 14, 16. The inset shows the zoomed-in part of the data shown in (a) near the cyclotron resonance. A series of deep (shallow) radiation-induced minima is marked by vertical lines (arrows).

Figure 2

$\rho \left(B\right)$ at different $f$, as marked, measured in sample A. Some examples of MPRs are marked by arrows. The traces are offset for clarity by $7\mathrm{\Omega }$.

Figure 3

$B^2$ (circles) vs $n$, for $f=377$ GHz (upper) and 354 GHz (lower), obtained from sample A. Solid (open) circles represent odd (even) $n$. Fits to the data (lines) using Eq. (4) yield $m^{☆}\approx 0.066m_0$ and $F_1\approx 56$ GHz.

Figure 4

$f^2$ vs $B^2$ for $n=7$ (circles), 13 (squares), and 19 (triangles), obtained from sample A. The fits to the data (lines) with $f^2=f_0^2+{(e/2\pi m^{☆})}^2{B}^2$ yield $m^{☆}=0.066m_0$. The inset shows $f_0^2$, obtained from the fits vs $n$, revealing linear relationship $f_0^2\sim n$. The slope of the linear fit (line) yields $F_1\approx 55$ GHz.

Figure 5

$\rho \left(B\right)$ at $T\approx 0.4$ K and different $f$, as marked, measured in sample A. Traces are offset for clarity by $7\mathrm{\Omega }$.