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Landau levels

The situation changes drastically in the presence of a high magnetic field perpendicular to the axis. As has been discussed in Sec. 2, Landau levels without dispersion appear at the Fermi level considerably, leading to a magnetic-field induced distortion [13,14]. [Pg.71]

Fig. 3. Electrical conductance of an MWCNT as a function of temperature at the indicated magnetic fields. The solid line is a fit to the data (see ref. 10). The dashed line separates the contributions to the magnetoconductance of the Landau levels and the weak localisation [10]. Fig. 3. Electrical conductance of an MWCNT as a function of temperature at the indicated magnetic fields. The solid line is a fit to the data (see ref. 10). The dashed line separates the contributions to the magnetoconductance of the Landau levels and the weak localisation [10].
Another example of systems where the pattern formation is observed is a two-dimensional electron liquid in a weak magnetic field with partially filled upper Landau levels. In such systems the uniform distribution of the charge density at the upper Landau level is unstable against the formation of a charge density... [Pg.190]

The magnetic field quantizes the motion of the quasi-particles in the plane perpendicular to the resulting levels are known as Landau levels, and the phenomenon is... [Pg.81]

Fig. 9.6 Quasi-Landau spectrum observed by laser excitation and field ionization of even parity, m = —2 states of Na in a magnetic field of 4.2 T. The arrows indicate the quasi-Landau levels, the highest energy magnetic states of each principal quantum number. The intermediate peaks are due to other levels. The numbers between the arrows give the level separation in units of fuoc. A WKB analysis predicts a spacing of 1.5 at W = 0, increasing with binding energy in agreement with the data. Relative intensities are not reliable due to... Fig. 9.6 Quasi-Landau spectrum observed by laser excitation and field ionization of even parity, m = —2 states of Na in a magnetic field of 4.2 T. The arrows indicate the quasi-Landau levels, the highest energy magnetic states of each principal quantum number. The intermediate peaks are due to other levels. The numbers between the arrows give the level separation in units of fuoc. A WKB analysis predicts a spacing of 1.5 at W = 0, increasing with binding energy in agreement with the data. Relative intensities are not reliable due to...
The elementary excitations mentioned so far are not related in any special way to the solid state and will therefore not be treated in this article. We will discuss here the following low-lying quantized excitations or quasi-particles which have been investigated by Raman spectroscopic methods phonons, polaritons, plasmons and coupled plasmon-phonon states, plasmaritons, mag-nons, and Landau levels. Finally, phase transitions were also studied by light scattering experiments however, they cannot be dealt with in this article. [Pg.88]

The use of lasers for the excitation of Raman spectra of solids has led to the detection of many new elementary excitations of crystals and to the observation of nonlinear effects. In this review we have tried to lead the reader to a basic understanding of these elementary excitations or quasi-particles, namely, phonons, polaritons, plasmons, plasmaritons, Landau levels, and magnons. Particular emphasis was placed upon linear and stimulated Raman scattering at polaritons, because the authors are most familiar with this part of the field and because it facilitates understanding of the other quasi-particles. [Pg.123]

Figure 44 Quantized Hall voltage of (TMTSF)2PF6 and phase diagram. The integers indicate the number of filled Landau levels in each subphase. (After Ref. 127.)... Figure 44 Quantized Hall voltage of (TMTSF)2PF6 and phase diagram. The integers indicate the number of filled Landau levels in each subphase. (After Ref. 127.)...
The quantization of the Hall resistance in the FISDW phases is indeed very reminiscent of the quantum Hall effect in the two-dimensional electron gas [136]. There is, however, an important difference between these two phenomena. In both cases the quantization requires a reservoir of nonconducting electronic states. This reservoir is provided either by localized states in the gap between conducting Landau levels or by the electron-hole (spin modulation) condensate for the two-dimensional electron gas and the FISDW of organics, respectively. [Pg.481]

Peticolas WL, Tsuboi M (1979) The Raman spectroscopy of nucleic acids. In Theophanides TM (ed) Infrared and Raman spectroscopy of biological molecules. Nato advanced study institute series, Series C, vol 43, D Reidel Publishing Company, Dordrecht Petrou A, McCombe BD (1991) Magnetospcctro.scopy of confined semiconductor systems. In Landwehr G, Rashba El (ed) Landau Level Spectroscopy, vol 27/1, North Holland Amsterdam Oxford New York Tokyo... [Pg.748]

The allowed states in k space are all lying on so-called Landau levels or Landau tubes. The annular cross-sectional area between neighboring Landau levels is Aa = 2ireB jh. All the electron states in k space which without fields... [Pg.62]

The Dingle reduction factor, Rd, describes the broadening of the otherwise sharp Landau levels due to scattering of the conduction electrons. The usual parameter which describes this scattering is the relaxation time r averaged over one cyclotron orbit [252]. This effect leads to a reduction factor similar to (3.8) for finite temperatures. As a useful parameter the so-called Dingle temperature... [Pg.65]

Finally, the factor Rs takes into account that the degeneracy of the energy levels is lifted by the Zeeman splitting and that two sets of Landau levels evolve. The energy difference between the split levels is... [Pg.65]

Fig. 4.4. The lower part shows the magnetization of a-(ET)2NH4Hg(SCN)4 vs reciprocal field at 0 = 26° and T = 0.5 K. The inset shows the FFT of the data. The upper part shows the corresponding Landau level number for levels with spin parallel and spin antiparallel to B. The solid fines are linear fits yielding a dHvA frequency F = (627 1) T... Fig. 4.4. The lower part shows the magnetization of a-(ET)2NH4Hg(SCN)4 vs reciprocal field at 0 = 26° and T = 0.5 K. The inset shows the FFT of the data. The upper part shows the corresponding Landau level number for levels with spin parallel and spin antiparallel to B. The solid fines are linear fits yielding a dHvA frequency F = (627 1) T...
In order to gain more information about the number of the two sets of Landau levels with spin up and spin down are plotted vs the corresponding inverse field in the upper part of Fig. 4.4. A simultaneous linear regression of both data sets results in an average dHvA frequency F = (627 1) T. The field B where the nth Landau level just crosses the FS is given by [249]... [Pg.84]


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See also in sourсe #XX -- [ Pg.66 , Pg.116 ]




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