What it means
The Planck constant divided by 2π, about 1.055 × 10⁻³⁴ joule-seconds. It sets the scale of quantum effects.
Read aloud in real formulas
iħ ∂ψ/∂t = Ĥψ
Aethel says
i h bar the partial derivative of psi with respect to t equals H hat psi
the Schrödinger equation
E = ħω
Aethel says
E equals h bar omega
the energy of a photon of angular frequency ω
Typing it
- LaTeX
- \hbar
- Unicode
- U+210F, U+0127
Formulas that use it
Questions
How do you say ħ out loud?
It is usually read “h bar”.
What does ħ mean in maths?
The Planck constant divided by 2π, about 1.055 × 10⁻³⁴ joule-seconds. It sets the scale of quantum effects.
How do you type ħ?
In LaTeX, write \hbar. Its Unicode code point is U+210F, U+0127.