The effect of confining potential on the stability of an electron crystal over liquid helium

2012 ◽  
Vol 38 (12) ◽  
pp. 1096-1099 ◽  
Author(s):  
V. V. Slavin ◽  
A. A. Krivchikov
Keyword(s):  
Liquid Helium ◽  
Confining Potential ◽  
The Stability ◽  
Electron Crystal

STUDY OF STRUCTURAL STABILITY OF WIGNER ELECTRON CRYSTAL

2000 ◽  
Vol 14 (17) ◽  
pp. 1767-1779 ◽  
Author(s):  
R. RAJESWARA PALANICHAMY ◽  
K. IYAKUTTI
Keyword(s):  
Ground State ◽  
Energy Surface ◽  
Three Dimensional ◽  
Present Calculation ◽  
Wannier Functions ◽  
Constant Energy ◽  
Bcc Lattice ◽  
The Stability ◽  
Ground State Energies ◽  
Electron Crystal

The ground state energies of the non-magnetic Wigner electron crystals corresponding to sc, bcc, fcc, diamond and perovskite structures are estimated and it is found that the bcc lattice still remains to be the stable known arrangement for three-dimensional Wigner electron crystal. Perovskite structure is not the stablest as claimed in a previous work, it is preferred only after fcc and sc. The stability is analysed taking different structures and assuming the possibility of the Wigner electrons having cubic or spherical constant energy surface, the region of occupation in momentum space, for a whole range of rs values (rs=20 to 200). The structure dependent Wannier functions, which give a proper localized representation for the Wigner electrons in the crystals are constructed and employed in the present calculation.

Energy relaxation between an electron crystal and liquid helium

1991 ◽  
Vol 159 (4-5) ◽  
pp. 277-278
Author(s):  
Yu.P. Monarkha ◽  
V.B. Shikin ◽  
D.C. Glattli ◽  
F.I.B. Williams
Keyword(s):  
Liquid Helium ◽  
Energy Relaxation ◽  
Electron Crystal

Colder specimens give a sharper impression: Prospects for higher resolution Electron Microscopy at liquid helium temperature

1989 ◽  
Vol 47 ◽  
pp. 816-817
Author(s):  
M.K. Lamvik
Keyword(s):  
Electron Microscopy ◽  
Mass Loss ◽  
Liquid Helium ◽  
Liquid Helium Temperature ◽  
Persistent Current ◽  
Helium Temperature ◽  
Electron Microscopes ◽  
Diffraction Patterns ◽  
Current Flows ◽  
The Stability

Designers of electron microscopes started putting liquid helium into their plans with the hopes of improving instrumental resolution. Liquid helium can be used to cool specimen stages within conventional lenses, but it can also be used to make some materials superconducting. Once started, current flows continuously in a superconducting coil because it faces negligible electrical resistance. Superconducting lenses were introduced in electron microscopy to take advantage of the high magnetic field strengths that could be generated as well as the stability of the persistent current in the superconducting coils. As time passed, it became clear that electronic regulation of power supplies could produce more than adequate current regulation to supercede the need for the persistent current maintained in a superconducting lens. Meanwhile, the realization grew that low temperatures might give another kind of advantage to electron microscopy of radiation-sensitive materials. The very low temperature might help protect sensitive specimens from damage.Several methods are available for detecting damage to specimens in electron microscopes. The loss of mass from specimens is one sign of radiation damage. A mass loss measurement with a liquid helium cooled stage seemed to show a significant reduction in mass loss; a different measurement that included a superconducting lens also indicated reduced damage. Another indicator of damage is the rate of fading of diffraction patterns of ordered specimens, and in this case it has been established that liquid helium temperature causes a moderate reduction of damage.

Nonlinear Features of Phonon–Ripplon Modes in the Electron Crystal Over Liquid Helium

2006 ◽  
Vol 144 (1-3) ◽  
pp. 35-48 ◽  
Author(s):  
V. E. Syvokon ◽  
Yu. Z. Kovdrya ◽  
K. A. Nasyedkin
Keyword(s):  
Liquid Helium ◽  
Nonlinear Features ◽  
Electron Crystal
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