microelectronvolt

The microelectronvolt, abbreviated as μeV, is a unit of energy in the metric system equal to one millionth of an electronvolt. Since 1 eV is the energy gained by an electron moving through a potential difference of one volt, 1 μeV corresponds to 1×10^-6 eV. In joules, 1 μeV equals approximately 1.602176634×10^-25 J.

Because energy and frequency are related by E = h f, a microelectronvolt corresponds to a frequency of about 2.42×10^8 Hz, i.e., roughly 240 megahertz. Using the Boltzmann constant k_B ≈ 8.617333262×10^-5 eV/K, 1 μeV corresponds to a temperature of about 0.0116 kelvin (11.6 millikelvin). These relationships help place μeV in physical contexts: it is a very small energy scale.

Applications and relevance: μeV-level energies are common in low-temperature and quantum-scale systems. They describe tiny energy splittings, gaps, or tunneling amplitudes in nanostructures such as quantum dots, quantum wells, and superconducting circuits. They also characterize transition energies and Zeeman splittings in spin systems under modest magnetic fields. In quantum information, qubit energy splittings and coherence scales are often expressed in μeV to reflect cryogenic operating conditions.

In summary, the microelectronvolt is a small unit of energy used to quantify energy differences and excitations in microscopic and quantum systems, linking energy to both frequency and temperature in practical ways.