Novel Attractive Force between Ions in Quantum Plasmas

Abstract

We report a new attractive force between ions that are shielded by degenerate electrons in quantum plasmas. Specifically, we show that the electric potential around an isolated ion has a hard core negative part that resembles the Lennard-Jones-type potential. Physically, the new electric potential is attributed to the consideration of the quantum statistical pressure and the quantum Bohm potential, as well as the electron exchange and electron correlations due to electron-1/2 spin within the framework of the quantum hydrodynamical description of quantum plasmas. The shape of the attractive potential is determined by the ratio between the Bohr radius and the Wigner-Seitz radius of degenerate electrons. The existence of the hard core negative potential will be responsible for the attraction of ions forming lattices and atoms or molecules, as well as for critical points and phase transitions in quantum plasmas at nanoscales.

Shukla–Eliasson attractive force: Revisited

“…The Coulomb interaction pressure is always negative, while, the pressure due to electron exchange changes the sign at the relativity parameter value around R ≃ 2 [6]. It should be noted that in the forthcoming calculations we have included the generalized form of the exchange energy, given by Salpeter, instead of that in ( [41]), since, the generalized exchange energy is valid for a wide electron number-density range. We further have neglected the effect of electron-correlation effect due to the vanishingly small contribution in the considered density regime ( [42]).…”

“…(10). We then appropriately decompose the integral following the procedure given by [41]. Therefore, the integral in Eq.…”

“…In order to obtain the dielectric constant for the present plasma model we use a standard procedure employed by Shukla & Eliasson ( [41]). The QHD equations given in Eqs.…”

“…More recently, by evaluating the electrodynamic potential of a moving test charge in a quantum plasma a modified Debye-Hückel (DH) potential, i.e., the ordinary DH potential coupled with an oscillatory term have found in quantum plasmas [40]. Such modified DH potential, particularly caused by the presence of electron degeneracy, interaction energies and the electron nonlocality effect, has been shown to lead to a new type of Lennard-Jones-like attractive force with a pronounced potential valley near the test particle ( [41]). The discovery of such new force in quantum plasmas has fundamental significance for the plasma coupling, crystallization and quantum transport effects in dense plasmas.…”

Metastable Bound State of Likely Charged Classic Coulomb Particles

“…This type of attraction, as is assumed in [2], allows to explain stability and big lifetime of compact plasmoids such as ball lightning. As is shown in [3], when plasma, featuring quantum-degenerated electrons is calculated, effective attraction of likely charged ions at certain distances occur, if electron-correlation potential is accounted for, which, in its turn, may result in phase transitions occurring in quantum plasma. Examples [1−3] may be referred to the type of bounding, which becomes possible due to collective interaction with background medium.…”