the zero-point energy is the lowest possible energy that a quantum mechanical  physical system may possess and is the energy of the ground state  of the system. The concept was first proposed by Albert Einstein  and Otto Stern in 1913. The term "zero-point energy" is a translation of the German Nullpunktenergie. All quantum mechanical systems have a zero point energy. The term arises commonly in reference to the ground state of the quantum harmonic oscillator and its null oscillations.