Equation 43 · Part 1 · Every Crystal Has Its Own Speed of Light

Symbol c_eff

c_{\mathrm{eff}} + v_d

c_{\mathrm{eff}}

What this part means

$c_e$ ff is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

Its job in the formula

$c_e$ ff is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

Full expressionSymbol c_effArticle meaning

The passage around this formula

The magnitude is the first surprise. In a driven or flowing lattice, the cone speed along the drift is $c_{\mathrm{eff}}$ + $v_d$ in one direction and $c_{\mathrm{eff}}$ - $v_d$ in the other, so the anisotropy between the along-drift and transverse directions is $\delta$ c/c $\simeq$ $v_d$ / $c_{\mathrm{eff}}$ — first order in the drift velocity, not the crushing second-order $v^2$ / $c^2$ $\sim$ 10^{-8} that made the 1887…

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Learn the underlying idea

A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.

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Sources cited in the surrounding passage

[13] Field-Angle Dependence of Sound Velocity in the Weyl Semimetal TaAs ↗

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