363 research outputs found
Unification Theory of Angular Magnetoresistance Oscillations in Quasi-One-Dimensional Conductors
We present a unification theory of angular magnetoresistance oscillations,
experimentally observed in quasi-one-dimensional organic conductors, by solving
the Boltzmann kinetic equation in the extended Brillouin zone. We find that, at
commensurate directions of a magnetic field, resistivity exhibits strong
minima. In two limiting cases, our general solution reduces to the results,
previously obtained for the Lebed Magic Angles and Lee-Naughton-Lebed
oscillations. We demonstrate that our theoretical results are in good
qualitative and quantitative agreement with the existing measurements of
resistivity in (TMTSF)ClO conductor.Comment: 6 pages, 2 figure
Interference Commensurate Oscillations in Q1D Conductors
We suggest an analytical theory to describe angular magnetic oscillations
recently discovered in quasi-one-dimensional conductor (TMTSF)2PF6 [see Phys.
Rev. B, 57, 7423 (1998)] and define the positions of the oscillation minima.
The origin of these oscillations is related to interference effects resulting
from an interplay of quasi-periodic and periodic ("commensurate") electron
trajectories in an inclined magnetic field. We reproduce via calculations
existing experimental data and predict some novel effects.Comment: 10 pages, 2 figure
Soliton Wall Superlattice in Quasi-One-Dimensional Conductor (Per)2Pt(mnt)2
We suggest a model to explain the appearance of a high resistance high
magnetic field charge-density-wave (CDW) phase, discovered by D. Graf et al.
[Phys. Rev. Lett. v. 93, 076406 (2004)] in (Per)2Pt(mnt)2. In particular, we
show that the Pauli spin-splitting effects improve the nesting properties of a
realistic quasi-one-dimensional electron spectrum and, therefore, a high
resistance Peierls CDW phase is stabilized in high magnetic fields. In low and
very high magnetic fields, a periodic soliton wall superlattice (SWS) phase is
found to be a ground state. We suggest experimental studies of the predicted
phase transitions between the Peierls and SWS CDW phases in (Per)2Pt(mnt)2 to
discover a unique SWS phase.Comment: 10 pages, 3 figures. Submitted to Physical Review Letters (February
19, 2007
Interference Effects Due to Commensurate Electron Trajectories and Topological Crossovers in (TMTSF)2ClO4
We report angle-dependent magnetoresistance measurements on (TMTSF)2ClO4 that
provide strong support for a new macroscopic quantum phenomenon, the
interference commensurate (IC) effect, in quasi-one dimensional metals. In
addition to observing rich magnetoresistance oscillations, and fitting them
with one-electron calculations, we observe a clear demarcation of
field-dependent behavior at local resistance minima and maxima (versus field
angle). Anticipated by a theoretical treatment of the IC effect in terms of
Bragg reflections in the extended Brillouin zone, this behavior results from
1D-2D topological crossovers of electron wave functions as a function of field
orientation.Comment: 14 page
Paramagnetic Intrinsic Meissner Effect in Layered Superconductors
Free energy of a layered superconductor with is calculated
in a parallel magnetic field by means of the Gor'kov equations, where
is a coherence length perpendicular to the layers and is an
inter-layer distance. The free energy is shown to differ from that in the
textbook Lawrence-Doniach model at high fields, where the Meissner currents are
found to create an unexpected positive magnetic moment due to shrinking of the
Cooper pairs "sizes" by a magnetic field. This paramagnetic intrinsic Meissner
effect in a bulk is suggested to detect by measuring in-plane torque, the upper
critical field, and magnetization in layered organic and high-T
superconductors as well as in superconducting superlattices.Comment: Submitted to Physical Review Letters on February 21st 200
Quantum Limit in a Parallel Magnetic Field in Layered Conductors
We show that electron wave functions in a quasi-two-dimensional conductor in
a parallel magnetic field are always localized on conducting layers. Wave
functions and electron spectrum in a quantum limit, where the "sizes" of
quasi-classical electron orbits are of the order of nano-scale distances
between the layers, are determined. AC infrared measurements to investigate
Fermi surfaces and to test Fermi liquid theory in Q2D organic and high-Tc
materials in high magnetic fields, H = 10-45 T, are suggested.Comment: 9 pages, 2 figures; Submitted to Physical Review Letter
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