[Paper Review] Pair production and ionizing radiation from superconductors

J. E. Hirsch|arXiv (Cornell University)|Aug 23, 2005

Superconducting Materials and Applications39 references4 citations

TL;DR

This paper proposes that within the theory of hole superconductivity, superconductors larger than a critical size can undergo real electron-positron pair production due to macroscopic charge separation, leading to emission of ionizing radiation up to 0.511 MeV. The effect arises from relativistic electron dynamics and macroscopic quantum coherence, predicting high-frequency radiation and potential health hazards if the theory is correct.

ABSTRACT

We show that an alternative theory of superconductivity recently proposed (theory of hole superconductivity) leads to the surprising consequence that real electron-positron pair production will occur for superconductors larger than a critical size. High frequency radiation with frequencies up to $0.511MeV/\hbar$ is predicted to be emitted from superconductors out of equilibrium. Attention to the possibility of harmful consequences is called for.

Motivation & Objective

• To test the viability of the theory of hole superconductivity by identifying unique, testable predictions not shared by conventional BCS-London theory.
• To investigate whether macroscopic charge separation in superconductors could lead to electron-positron pair production analogous to supercritical atoms.
• To explore the implications of macroscopic quantum coherence and relativistic effects in superconducting states for high-energy phenomena.
• To assess the potential health risks of ionizing radiation from superconductors if the theory of hole superconductivity is correct.

Proposed method

• Using the theory of hole superconductivity, the paper models superconductors as macroscopic systems with excess negative charge at the surface and positive charge in the interior, analogous to giant atoms.
• Applying relativistic quantum mechanics, the paper derives a critical radius R_c where the electrostatic potential energy of an electron in the positive core reaches 2m_e c^2, enabling pair production.
• The model uses the London penetration depth λ_L and condensation energy ε to calculate the critical radius R_c = λ_L (6m_e c^2 / 5ε)^1/2.
• The paper analyzes spin currents in the superconducting ground state, predicting that their decay could emit high-frequency radiation up to 0.511 MeV/ħ.
• It draws analogies to Dirac’s hole theory and supercritical atoms, where Z > 137 or Z > 172 leads to spontaneous pair creation.
• The analysis extends the BCS wavefunction to include superpositions of different particle number states, arguing this is physically necessary under the hole superconductivity framework.

Experimental results

Research questions

• RQ1 Can superconductors larger than a critical size exhibit real electron-positron pair production due to macroscopic charge separation?
• RQ2 Does the theory of hole superconductivity predict the emission of ionizing radiation with frequencies up to 0.511 MeV/ħ?
• RQ3 What is the critical radius R_c at which pair production becomes energetically favorable in a superconducting sphere?
• RQ4 How does macroscopic quantum coherence in superconductors enable the emergence of MeV-scale phenomena from μeV-scale pairing energies?
• RQ5 What are the implications of the BCS wavefunction including superpositions of different particle number states under the hole superconductivity model?

Key findings

• A critical radius R_c = λ_L (6m_e c^2 / 5ε)^1/2 is derived, above which electron-positron pair production becomes energetically favorable in superconductors.
• The theory predicts emission of high-frequency radiation up to 0.511 MeV/ħ from superconductors out of equilibrium, due to spin current decay and pair annihilation.
• Ionizing radiation from pair production and annihilation could pose a health hazard if the theory of hole superconductivity is correct.
• The model suggests that the BCS wavefunction must include superpositions of different particle number states to be physically consistent under hole superconductivity.
• The paper argues that the superconducting state, due to macroscopic coherence, can harness small local energies to produce large-scale relativistic effects and high-energy phenomena.
• The theory implies that superconductors could behave like 'giant atoms' with charge asymmetry on macroscopic scales, enabling phenomena typically restricted to extreme astrophysical conditions.