Different components of far-infrared photoresponse of quantum Hall detectors

Kalugin, Nikolai G.; Nachtwei, G.; Vasilyev, Yu. B.; Suchalkin, S.; Eberl, K.

doi:10.1063/1.1492315

Cited by 16 publications

(16 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Bolometric effects are responsible for at least some of these nonresonant features. 28 The data show that the ESR feature for Sample A is at a lower magnetic field than for Sample B. If only the Zeeman effect were important, we would expect the opposite to be true because the FIR frequency is higher and the well width is smaller for Sample A.…”

mentioning

confidence: 89%

Spectroscopy of Rashba spin splitting in InSb quantum wells

et al. 2004

View full text Add to dashboard Cite

We use electron spin resonance in the far infrared to probe the Landau-level spin splitting in symmetric and asymmetric InSb quantum wells. The asymmetric wells exhibit a strong deviation in behavior from the symmetric wells at low magnetic fields with apparent g factors far in excess of the bulk g factor of InSb. These asymmetry-induced shifts in the spin resonance depend on Landau-level The study of electron spin phenomena in semiconductor heterostructures has intensified dramatically in recent years. The field, "spintronics" has emerged with the purpose of developing devices combining the charge and spin degrees of freedom. In particular, spin splitting caused by bulk inversion asymmetry and structural inversion asymmetry (SIAoften called Rashba splitting) has attracted much attention. Understanding the spin-orbit interaction caused by SIA, which is predicted to lead to spin splitting even without an applied magnetic field, 1,2 is important for developing spinbased devices. To date, experimental evidence for Rashba splitting in two-dimensional electron systems (2DESs) has been chiefly confined to the observed beating of Shubnikov-de Haas (SdH) oscillations 3,4 that is presumed to arise from different populations of electron spin orientations. This beating has been interpreted in a number of heterostructures [3][4][5][6][7][8][9][10][11][12][13][14][15][16] to deduce the Rashba parameter ␣, which is expected to depend on materials parameters and the electric field. The zero-field spin splitting has also been inferred from Raman-scattering spectra 17 in GaAs and weak anti-localization measurements in InGaAs quantum wells 18 . In this paper, we report on electron spin resonance (ESR) experiments on 2DESs in InSb quantum wells. By observing transitions between states with the same Landau level index but opposite spin orientations, we directly measure the spin splitting as a function of applied magnetic field B. In addition to the B = 0 spin splitting, the Rashba model 1 predicts considerable modification of the Landau-level energy structure at nonzero B for asymmetric heterostructures, which has not been previously confirmed. Because of the large effective g factor and large predicted Rashba effect, 6 the spin splitting in InSb-based 2DESs should occur at far infrared frequencies for B Ͻ 10 T. Our experiments demonstrate that the Rashba effect is relatively strong in InSb quantum wells and that ESR is a powerful technique for studying the Rashba effect.Our samples are InSb single quantum wells of widths 30 and 20 nm with Al 0.09 In 0.91 Sb barrier layers that are ␦ doped with Si. The Si ␦ layers are located either singly on one side of the quantum well (asymmetric samples) or equidistant on both sides of the quantum well (symmetric samples). The ␦-doped layers within the barrier layers are typically located 70 nm from the well center. The barrier layers on the substrate and surface sides of the wells are 3 m and 160 nm thick, respectively. Silicon dopants are placed near the surface to limit surface depletion. ...

show abstract

mentioning

confidence: 89%

Spectroscopy of Rashba spin splitting in InSb quantum wells

et al. 2004

View full text Add to dashboard Cite

show abstract

“…kind [15][16][17][18][19][20][21] was done in an ideal quantum Hall state and explained by the heating effect due to the nanosecond to microsecond terahertz pulses they employed. Therefore, the idea of light-induced IQHE has not been explored yet.…”

mentioning

confidence: 99%

Light-induced electron localization in a quantum Hall system

et al. 2017

View full text Add to dashboard Cite

An insulating bulk state is a prerequisite for the protection of topological edge states 1 . In quantum Hall systems, the thermal excitation of delocalized electrons is the main route to breaking bulk insulation 2 . In equilibrium, the only way to achieve a clear bulk gap is to use a high-quality crystal under high magnetic field at low temperature. However, bulk conduction could also be suppressed in a system driven out of equilibrium such that localized states in the Landau levels are selectively occupied. Here we report a transient suppression of bulk conduction induced by terahertz wave excitation between the Landau levels in a GaAs quantum Hall system. Strikingly, the Hall resistivity almost reaches the quantized value at a temperature where the exact quantization is normally disrupted by thermal fluctuations. The electron localization is realized by the long-range potential fluctuations, which are a unique and inherent feature of quantum Hall systems. Our results demonstrate a new means of e ecting dynamical control of topology by manipulating bulk conduction using light.The integer quantum Hall effect (IQHE) is a universal phenomenon observable in two-dimensional electron systems under high magnetic field (B). The Hall resistivity (ρ xy ) is quantized and the longitudinal resistivity (ρ xx ) becomes zero irrespective of the detailed properties of the host materials [2][3][4][5][6][7] . This universality has lead to a new physical concept of topological invariant that defines the quantized value of ρ xy (ref. 8). In systems with sample boundaries, edge metallic states appear according to the bulk/edge correspondence 9 and carry quantized Hall current. The edge states are protected by the bulk gap between the Landau levels (LLs), which prohibits the scattering between macroscopically separated edge states 10,11 . In realistic situations, we need to take into account the impurity and finite-temperature effect. The LLs are broadened with delocalized states in the centre, sandwiched by localized states induced by Anderson localization 12,13 (Fig. 1d). At finite temperatures, the delocalized states are broadened and thermally populated, which makes the bulk conductive 2,14 . As a result, the scattering between edge states is allowed and ρ xy (ρ xx ) is no longer quantized (zero).In this paper, we demonstrate a transient suppression of bulk conduction and a recovery of the quantized ρ xy by selectively populating the localized electronic states. A direct way to manipulate the electron distribution in LLs is inter-LL transition by resonant light absorption (typically in the terahertz frequency region). To verify this strategy for realizing light-induced IQHE, we performed transient Hall measurements on a quantum Hall system with a non-equilibrium electron distribution induced by picosecond terahertz pulse excitation. Previous research of this kind [15][16][17][18][19][20][21] was done in an ideal quantum Hall state and explained by the heating effect due to the nanosecond to microsecond terahertz pulses they empl...

show abstract

“…We found various contributions to the PR: non-resonant (bolometric) and resonant (related to the cyclotron resonance) contributions to the longitudinal and to the Hall resistance of the samples [3][4][5][6][7]. By reversing the direction of the magnetic field we were able to distinguish between longitudinal and Hall contributions to the PR.…”

Section: Optically Induced Dissipation In Qhssmentioning

confidence: 87%

“…Hall bars and Corbino-shaped devices patterned from GaAs/GaAlAs heterojunction wafers [3][4][5][6][7][8][9][10][11][12][13][14][15][16]38] and from HgTe/HgCdTe quantum well wafers [14][15][16][17][18] were exposed to THz waves.…”

Section: Optically Induced Dissipation In Qhssmentioning

confidence: 99%

“…This is because the energy gap between adjacent Landau levels (LLs) of ∆E LL ≈ 10 meV corresponds to photons of electromagnetic waves with a wavelength of λ ≈ 125 µm. Thus, sensitive and fast THz detectors with spectral selectivity [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] can be made on the basis of QHSs. However, it takes effort to cool the samples to temperatures at or below 4.2 K and to expose the samples to magnetic fields of typically B > 4 T. As this requires helium cooling of the samples and the application of superconducting magnets, QH THz detectors are not particularly appropriate for widespread use.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Optically and electrically induced dissipation in quantum Hall systems

Nachtwei

Stellmach

Vasile

et al. 2008

Physica Status Solidi (b)

Self Cite

View full text Add to dashboard Cite

IntroductionThe quantum Hall effect (QHE) [1] is interesting with respect to understanding its physical mechanisms and with respect to its applications. Besides the use of the QHE to maintain a resistance standard on the basis of a macroscopic quantum effect [2], it is also possible to use quantum Hall systems (QHSs) to detect THz waves. This is because the energy gap between adjacent Landau levels (LLs) of ∆E LL ≈ 10 meV corresponds to photons of electromagnetic waves with a wavelength of λ ≈ 125 µm. Thus, sensitive and fast THz detectors with spectral selectivity [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] can be made on the basis of QHSs. However, it takes effort to cool the samples to temperatures at or below 4.2 K and to expose the samples to magnetic fields of typically B > 4 T. As this requires helium cooling of the samples and the application of superconducting magnets, QH THz detectors are not particularly appropriate for widespread use. These detectors have, however, the unique simultaneous properties of high sensitivity,

show abstract

Different components of far-infrared photoresponse of quantum Hall detectors

Cited by 16 publications

References 14 publications

Spectroscopy of Rashba spin splitting in InSb quantum wells

Spectroscopy of Rashba spin splitting in InSb quantum wells

Light-induced electron localization in a quantum Hall system

Optically and electrically induced dissipation in quantum Hall systems

Contact Info

Product

Resources

About