Magnetotunneling spectroscopy of polarons in a quantum well of a resonant-tunneling diode

Fine structure of phonon replicas in a tunnel spectrum of a GaAs quantum well

“…where E QW (p) is the 2D dispersion of electrons in the QW, ∆z = z 1 − z 2 is a tunneling length, where z 1 and z 2 are electron averaged positions in the emitter and QW states, and B is a magnetic field. In accordance with this equation, the magnetic dependence of U peak reproduces the 2D dispersion of the electrons in the direction perpendicular to the magnetic field 4 . The crucial point is to determine the leverage factor because it is an aspect ratio between voltage and energy difference of the subband levels.…”

“…Anticrossing is described in more detail in Ref. 4. We approximate the experimental data U peak (B) by the parabolic function F = A • B 2 + const, and we obtain the value A = 0.00188 V /T 2 .…”

“…Resonant tunneling spectroscopy is a powerful method to investigate numerous effects in low-dimensional structures, such as interactions of electrons with each other 1,2 , phonons 3 , polarons 4 and plasmons 5 . Resonant-tunneling diodes (RTD) have a huge potential for practical applications 6 because the diodes are the fastest solidstate devices operating up to 1 THz 7 .…”

Magnetotunneling in resonant tunneling structures with spin − orbit interaction

“…The problem of electron-LO phonon interaction in a 2DEG, being of fundamental significance, has received a considerable attention 16,65,66 . Polaron effects have been studied using cyclotron resonance 67 in a quantum well, or by investigating the I-V curve features in magnetotunnelling in perpendicular 9,12 and in-plane 15 is not simple to establish, owing to the fact that the self-energy is found as a self-consistent solution, but a rough estimate is that the self-energy scales as the square root of U 2 LO . The significance of the phonon replicas in the RTS is that they provide an additional channel for electrons tunnelling through the RTS.…”

“…When a perpendicular magnetic field is applied, the 2DEG density of states (DOS) collapses into discrete Landau levels (LLs) thus pronouncing the resonant features in scattering. For this reason, magnetotunnelling experiments in RTSs [5][6][7][8][9][10][11][12][13][14][15] have been established as an important tool in investigating the 2DEG physics.…”