Phonon design system

Stochast grammar · dark-only · M0 foundation
pre
lec
post
rec
Color · semantic tokens
Surface
bg#0a0b0d
surface#101216
surface-2#15181d
surface-3#1b1f27
border / border-2#23262d
Text
text#e7e9ec
text-2#b6bbc2
muted#878d96
faint#5a606a
ghost#3c424b
Accent & status
accent · deductive#5b8cff
teal · inductive#3fb59b
success / warning#4cb784
error#d65b6b
violet · lecture#9b7cf0
math-var#de7bb1
Chart marks · strongest chroma
Typography · role-based, narrow
IBM Plex Mono — operational
0.67 eV
Eg = Ec − Ev
weak topics · accuracy · 04 of 06
IBM Plex Sans — narrative

In an indirect bandgap, the conduction-band minimum and valence-band maximum sit at different crystal momenta, so an electron cannot transition by absorbing a photon alone — the lattice must supply the missing momentum through a phonon.

Math-var highlighting in problem prose (Stitch port)

Given a silicon sample at T = 300 K, the intrinsic carrier concentration is n_i = 1.5×10¹⁰ cm⁻³. If the sample is doped with 10¹⁶ cm⁻³ of phosphorus, calculate the equilibrium hole concentration p_0.

Formula slabs · KaTeX
n=Nc exp⁡ ⁣(−Ec−EFkBT)n = N_c \, \exp\!\left(-\frac{E_c - E_F}{k_B T}\right)
F1/2(η)=∫0∞x1/21+e x−η dxF_{1/2}(\eta) = \int_0^{\infty} \frac{x^{1/2}}{1 + e^{\,x-\eta}}\, dx

Inline math also works: Δk=kc−kv≠0\Delta k = k_c - k_v \neq 0 implies phonon absorption or emission.

Components · panels, not cards
Status badges
CompleteIn progressDue soonWeakLectureDraft
Buttons
⌘K
Mode switch · segmented
deductive
Numeric input · unit affordance
MCQ option states
ANothing — the photon suffices18%
BSelected, pre-submit
BA phonon to conserve crystal momentum71%
CA second identical photon11%
Why

Silicon's extrema sit at different k. The photon supplies energy but ~no momentum, so a phonon absorbs or emits the Δk to satisfy conservation.

band diagram · E vs k · widget zone
Data surfaces · high contrast
68%
Pre-lecture100%
Post-lecture60%
Recitation prep25%
Class accuracy · last 7+6%
Heatmap cells · wrong-rate
9%34%61%78%
Sparkline · engagement