Zero-Point Energy
The lowest possible quantum mechanical energy state that a physical system may possess at absolute zero temperature (0 K).
Governing formula
E₀ = ½ ℏ ω (for harmonic oscillator)
SI unit
eV or Joules
In depth
Zero-point energy is a direct consequence of the Heisenberg uncertainty principle. If a bound particle had zero kinetic energy, its momentum would be precisely zero, requiring infinite spatial extent.
Examples in the real world
Preventing liquid Helium-4 from freezing into a solid at atmospheric pressure even when cooled to 0 K.