Question: What is the type of particle of the concept that was proposed by the Soviet physicist who also discovered the theory of superfluidity?
Sentence (from "Lev Landau"): His accomplishments include the independent co-discovery of the density matrix method in quantum mechanics (alongside John von Neumann), the quantum mechanical theory of diamagnetism, the theory of superfluidity, the theory of second-order phase transitions, the Ginzburg–Landau theory of superconductivity, the theory of Fermi liquid, the explanation of Landau damping in plasma physics, the Landau pole in quantum electrodynamics, the two-component theory of neutrinos, and Landau's equations for "S" matrix singularities.
Relevant evidence: Yes