Far-infrared magnetospectroscopy of the Landau-level structure in graphite

1979 ◽  
Vol 19 (8) ◽  
pp. 4224-4230 ◽  
Author(s):  
R. E. Doezema ◽  
W. R. Datars ◽  
H. Schaber ◽  
A. Van Schyndel
Keyword(s):  
Landau Level ◽  
Level Structure ◽  
Far Infrared

Far‐infrared photovoltaic effect in a Landau level diode

1989 ◽  
Vol 55 (2) ◽  
pp. 162-164 ◽  
Author(s):  
C. T. Liu ◽  
B. E. Kane ◽  
D. C. Tsui ◽  
G. Weimann
Keyword(s):  
Landau Level ◽  
Photovoltaic Effect ◽  
Far Infrared

FILLING LANDAU LEVELS: FERMI SEA GROUND STATE ENERGY, COMPETING INTERACTIONS AND MARGINAL DISPERSIONS IN GENERALIZED FLUX PHASES

1992 ◽  
Vol 06 (05n06) ◽  
pp. 563-583
Author(s):  
Benoit Douçot ◽  
Franco Nori ◽  
R. Rammal
Keyword(s):  
Kinetic Energy ◽  
Landau Level ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Level Structure ◽  
Minimum Energy ◽  
Landau Levels ◽  
Integer Number ◽  
Local Minima

ABSTRACT: We review recent studies on the energetics of fermions confined to a two dimensional square lattice, and the relations of these results to mean-field approaches to the t−J model. Our goal has been to compute the kinetic energy of the Fermi sea of the spinless fermions for any value of the (1) fermion concentration, (2) magnetic flux, and (3) frustration. For the unfrustrated case, we confirm that the ground state energy, χ(Φ), is a minimum for Φ=π(1−δ), which corresponds to one flux quantum per spinless fermion. We then proceed to do a systematic study of frustration effects, coming from longer range couplings, which modify the picture obtained for the unfrustrated case. The frustrating influence of the kinetic energy of the holes (e.g., by breaking magnetic bonds and suppressing the long-range order present in the undoped systems) is the main focus of this work. We find that, in general, E(Φ) always exhibits cusp-like minima which position moves linearly as a function of the fermion density x. Frustration can induce a competition between different local minima. By first considering the local minima for one particle only, we can understand most of the qualitative features of E(Φ). These local minima occur at simple rational fractions of Φ0, and when the flux slightly deviates from these values a one-particle Landau level structure develops. It is precisely such a spectrum that generates a family of cusps that “move away” from the original flux value as x is increased. Every cusp corresponds to an integer number of filled Landau levels, and the minimum energy cusp corresponds to the one level case. Furthermore, we use perturbation theory, valid for low fermion density x, in order to analyze quantitatively the behavior of the cusp-like energy minima; which originate from the Landau level structure when the flux is close to a rational value. If the flux is slightly away from a given rational value [Formula: see text] each of the q subbands generates a secondary Landau level structure. We have derived a t2−t3 phase diagram indicating regions of similar behavior (i.e., adiabatic continuations can be performed with each region, preserving the E(Φ) structure) and the boundaries between them. We have studied several points belonging to those boundaries and found that anomalous behavior, (e.g., cancelation of the k2 term in the dispersion relation) induced by frustration, can occur.

Far-infrared surface-Landau-level spectroscopy in Bi

1975 ◽  
Vol 12 (8) ◽  
pp. 2883-2892 ◽  
Author(s):  
M. Wanner ◽  
R. E. Doezema ◽  
U. Strom
Keyword(s):  
Landau Level ◽  
Far Infrared ◽  
Landau Level Spectroscopy

Landau Level Lifetimes in an InAs/AlSb Quantum Well Determined by a Picosecond Far-Infrared Pump-Probe Technique

1997 ◽  
Vol 204 (1) ◽  
pp. 155-158 ◽  
Author(s):  
B. N. Murdin ◽  
M. Kamal-Saadi ◽  
C. M. Ciesla ◽  
C. R. Pidgeon ◽  
C. J. G. M. Langerak ◽  
...  
Keyword(s):  
Quantum Well ◽  
Landau Level ◽  
Far Infrared ◽  
Pump Probe ◽  
Probe Technique

scholarly journals Spectral Function Analysis of Fermi Liquids and of Composite Fermions in A Finite Magnetic Field: Renormalised Gaps

1997 ◽  
Vol 11 (12) ◽  
pp. 1477-1502 ◽  
Author(s):  
S. Curnoe ◽  
P. C. E. Stamp
Keyword(s):  
Landau Level ◽  
Function Analysis ◽  
Level Structure ◽  
Quantum Hall ◽  
Composite Fermions ◽  
Filling Fraction ◽  
Fractional Quantum ◽  
Fractional Quantum Hall ◽  
Self Energy ◽  
Level Quantization

We consider the self-energy and quasiparticle spectrum, for both electrons interacting with phonons, and composite fermions interacting with gauge fluctuations. In both cases we incorporate the singular structure arising from Landau level quantization in a finite field. This is then used to determine the renormalised gap between the Fermi energy and the first excited states. The electron–phonon problem is treated for both Debye and Einstein phonons. In the case of composite fermions, it is found that the singular Landau level structure strongly affects the renormalised gap in the intermediate coupling regime, which is relevant to experiments on the fractional quantum Hall effect. We compare our findings with measurements of the gap in fractional Hall states with filling fraction ν near ν=1/2.

LANDAU LEVEL SPECTROSCOPY OF DIRAC-LIKE FERMIONS IN MULTILAYER GRAPHENE

2009 ◽  
Vol 23 (12n13) ◽  
pp. 2665-2666
Author(s):  
M. POTEMSKI
Keyword(s):  
Silicon Carbide ◽  
Optical Properties ◽  
Landau Level ◽  
Visible Region ◽  
Far Infrared ◽  
Dispersion Relations ◽  
Thin Layers ◽  
Multilayer Graphene ◽  
Graphite Sheet ◽  
Graphene Layers

The results of spectroscopic (magneto-transmission and Raman scattering) studies1–8 of multilayers of carbon which are thermally decomposed from carbon-terminated surface of silicon carbide, and of thin layers of highly oriented pyrolytic and natural graphite were presented. Those carbon multilayers on silicon carbide which are not directly affected by the SiC / C interface and which in consequence are nearly charge neutral show the magneto-optical properties identical with the properties characteristic of a single graphite sheet, graphene. Inter Landau level transitions in this multilayer graphene have been studied in a wide spectral range from far-infrared to almost visible region. The dispersion relations of electronic states are found to reflect the form of the Dirac cone with almost perfect electron-hole symmetry and only weak deviations from linearity at high energies. Cyclotron resonance transition in multilayer graphene can be observed in magnetic fields down to 40 mT, and its width is practically independent on temperature up to 300 K. Such parameters as carrier mobility and minimal conductivity as well as the possibility to probe the immediate vicinity of the Dirac point were evaluated and discussed in detail. For comparison, the magneto-optical properties of thin layers of bulk graphite were also reported. The Dirac like electronic dispersion relations are also found in these systems, but only in the vicinity of the particular (H) point of the Brillouin zone. In general, the measured spectra are, however, more complex and reflect the three-dimensional character of graphene layers with Bernal stacking. Note from Publisher: This article contains the abstract only.

scholarly journals Remarks on fermions in a dipole magnetic field

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Jeff Murugan ◽  
Jonathan P. Shock ◽  
Ruach Pillay Slayen
Keyword(s):  
Magnetic Field ◽  
Landau Level ◽  
Strong Field ◽  
Level Structure ◽  
Small Radius ◽  
Current Loop ◽  
Spinless Fermion ◽  
Lowest Landau Level ◽  
Spinless Case ◽  
The Magnetic Field

Abstract This work is a continuation of our recent study of non-relativistic charged particles, confined to a sphere enclosing a magnetic dipole at its center [1]. In this sequel, we extend our computations in two significant ways. The first is to a relativistic spin-$$ \frac{1}{2} $$ 1 2 fermion and the second concerns the interpretation of the physics. Whereas in [1] we speculated on the possibility of observing such condensed matter systems in the astrophysics of extreme magnetic sources such as neutron stars, the physical systems in this study are more down-to-earth objects such as a C60 fullerine enclosing a current loop. We unpack some of the details of our previous analysis for the spinless fermion on the dipole sphere and adapt it to solve the eigenvalue problem for the single-particle Dirac Hamiltonian. In the strong-field/small-radius limit, the spectrum of the spin-$$ \frac{1}{2} $$ 1 2 Hamiltonian, like the spinless case, exhibits a Landau level structure in the |m| ≪ Q regime. It features a new, additional (approximately) zero-energy lowest Landau level which persists into the |m| < Q regime. As in the spinless system, the spectrum exhibits level-crossing as the strength of the magnetic field increases, with the wavefunctions localising at the poles in the strong-field/small-radius limit.

Sign in / Sign up

Export Citation Format

Share Document