Coulomb instability

Interfacial Electrokinetic Flow, Fig. 1 Liquid meniscus issuing from a 100 (xm capillary in DC electrospraying showing its conical shape and a thin jet that emanates from the meniscus tip. The Jet subsequently breaks up due to hydrodynamic or Coulombic instabilities to generate very small aerosol drops... 

The counter-ion accumulation at the tip then creates a Coulombic repulsion force which causes the tip to disintegrate into a thin jet that emanates from meniscus when the surface tension force holding the drop together is exceeded, as shown in Fig. 1. This jet subsequently breaks up due to hydrodynamic or Coulombic instabilities to form a spray of small liquid drops. As the accumulated charge at the tip is transferred from the meniscus tip to the jet and subsequently to the drops, each individual drop carries a net charge. Since the size of the ejected drop shrinks during its flight due to evaporation, the repulsive force builds... 

The charged droplets produced by the spray needle shrink due to solvent evaporation while the charge remains constant. The energy required for the evaporation is provided by the thermal energy of the ambient air. As the droplet gets smaller, the repulsion of the charges at the surface increases and at a certain droplet radius the repulsion of the charges overcomes the cohesive force of the surface tension. A Coulomb instability results and leads... 

Monte Carlo simulations [17, 18], the valence bond approach [19, 20], and g-ology [21-24] indicate that the Peierls instability in half-filled chains survives the presence of electron-electron interactions (at least, for some range of interaction parameters). This holds for a variety of different models, such as the Peierls-Hubbard model with the onsite Coulomb repulsion, or the Pariser-Parr-Pople model, where also long-range Coulomb interactions are taken into account ]2]. As the dimerization persists in the presence of electron-electron interactions, also the soliton concept survives. An important difference with the SSH model is that neu-... 

Tunnelling recombination of primary F, H pairs can result either in closely spaced v+,i pairs (the so-called a, I centres) which annihilate immediately due to Coulomb interaction and a consequently large instability radius. However some i ions occur in crowdion configurations, and leave vacancy moving away up to 4-5 ao even at 4 K [31]. The distinctive feature of tunnelling recombination is its temperature independence, which makes it one of the major low-temperature secondary processes in insulating solids with defects. 

The next stage in the defect formation process involves the transfer of energy from the electronic excitation to the lattice. Although the exact details of the necessary excited states which induce the instability are the subject of some controversy, it is known that the basic cause of the transformation is the coulombic repulsive interaction between the electron and the X2 molecule. 

Ph. Ghosez, X. Gonze and J.-P. Michenaud, "Coulomb interaction and ferroelectric instability of BaTiOs," Europhys. Letters 33 (1996), 713-718. 

Atoms are first stripped of their electrons at very high temperatures this creates a plasma (ionized gas) of positive ions. Then the positive ions must be brought into close enough proximity, so that the strong attractive force between nucleons can overwhelm the Coulomb repulsion between them. Magnetic fields can confine hot plasmas of ions, provided that collective instabilities of these plasmas can be controlled. For a successful nuclear fusion reactor, three requirements must be met (1) The density of the plasma must exceed some critical value p. (2) The plasma confinement time must exceed some critical value t. (3) The temperature of the plasma must exceed some critical value 9... 

The spin-Peierls 2kF instability usually occurs when U is big and is originated by spin-phonon interactions. As in the CDW case, in real systems, the interchain Coulomb interactions couple the SDW and may lead to phase transitions at T > 0. 

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