diff --git a/layout.typ b/layout.typ index 2f0e68b..0ea8d26 100644 --- a/layout.typ +++ b/layout.typ @@ -46,7 +46,7 @@ show math.equation: set text(weight: 400) // Formatting for regular text - set par(justify: true, leading: 1em, first-line-indent: indent, spacing: 1em) + set par(justify: true, leading: 1em) show heading: set block(spacing: 0.7em) set terms(separator: [ -- ]) @@ -181,7 +181,7 @@ ) // TODO: make the same style as LaTeX: 1. | (a) | i. | A. - outline(depth: 3, indent: 1cm, title: text(size: 14pt, "Saturs")) + outline(depth: 3, indent: indent, title: text(size: 14pt, "Saturs")) body } diff --git a/main.typ b/main.typ index be005d4..0a892f7 100644 --- a/main.typ +++ b/main.typ @@ -1,10 +1,45 @@ #import "@preview/fletcher:0.5.7" as fletcher: diagram, edge, node +#import "@preview/gentle-clues:1.2.0": * #import "@preview/physica:0.9.5": bra, braket, ket, ketbra #import "@preview/quill:0.6.1": * #import "@preview/quill:0.6.1" as quill: tequila as tq #import "layout.typ": indent-par, project -#show: project.with(title: [Kvantu skaitļošana], authors: ("Kristofer Solo",)) +#show: project.with(title: [Quantum Computation Cheatsheet], authors: ( + "Kristofers Solo", +)) + += Bre-Ket Notation +== Ket $ket(psi)$ +Represents a column vector for a quantum state. +$ ket(psi)=alpha ket(0)+beta ket(1) <==> vec(alpha, beta) $ + +=== Basis states +$ ket(0)=vec(1, 0), ket(1)=vec(0, 1) $ + +== Bra $bra(psi)$ +Represents a *conjugate transpose vector (kompleksi saistīts)* (row vector) of +$ket(psi)$. +$ "If " ket(psi) = vec(alpha, beta) ", then" ket(psi)=(a^* space.quad b^*) $ + +== Scalar Product $braket(phi, psi)$ +Inner product of two states. +$ + "If " ket(phi) = gamma ket(0)+ delta ket(1) ", then" + braket(phi, psi)= gamma^* alpha + delta^* beta +$ + +=== Orthogonal states +$ braket(phi, psi)=0 $ + +== Projection $braket(i, psi)$ +Amplitude of the basis state $ket(i)$ in $ket(psi)$. + +For $ket(psi)=alpha ket(0) + beta ket(1) : +braket(0, psi)=alpha, +psi braket(1, psi)=beta$. + +Probability of measuring state $ket(i): P(i)=abs(braket(i, psi))^2$ = Fundamentals == Qubit (Kvantu bits) @@ -13,7 +48,8 @@ $ ket(0)=vec(1, 0), ket(1)=vec(0, 1) $ === Superposition A qubit can be in a linear combination of basis states: -$ket(psi)=alpha ket(0)+ beta ket(1)$, where $alpha, beta in CC$ are probability amplitudes. +$ ket(psi)=alpha ket(0)+ beta ket(1) ", where "alpha, beta in CC $ +are probability amplitudes. === Normalization $ abs(alpha)^2 + abs(beta)^2 = 1 $ @@ -25,13 +61,38 @@ Geometric representation of a single qubit state: $ ket(psi)=cos theta/2 ket(0)+ e^(i phi) sin theta/2 ket(1) $ == Measurement (Mērījumi) -- Projective measurement in the computational basis ${ket(0), ket(1)}$. +- Projective measurement in the basis (e.g. computational ${ket(0), ket(1)}$ or + Hadamard ${ket(+), ket(-)}$). - If state is $ket(psi)=alpha ket(0) + beta ket(1)$: - Outcome $0$: probability $P(0)=abs(braket(0, psi))^2=abs(alpha)^2$. Post-measurement state: $ket(0)$. - Outcome $1$: probability $P(1)=abs(braket(1, psi))^2=abs(beta)^2$. Post-measurement state: $ket(1)$. -- Measurement collapses the superposition. -- Measurement operators: $M_0=ket(0)bra(0)$, $M_1 = ket(1)bra(1)$. - $sum_m M_m^dagger M_m=I$. +- Measurement collapses the superposition (mērījums maina kvantu bitu (observer effect)). + +=== Measurement operators +$ + M_0=ket(0)bra(0) , + M_1 = ket(1)bra(1) \ + sum_m M_m^dagger M_m=I +$ + +=== Measuring in $ket(+), ket(-)$ basis +$ + ket(+)=1/sqrt(2)(ket(0)+ket(1)), + ket(-)=1/sqrt(2)(ket(0)-ket(1)) +$ + +To measure $ket(0)$ in this basis: $ket(0)=1/sqrt(+)+1/sqrt(2)ket(-)$. +$ + P(+)=abs(braket(+, 0))^2=1/2, + P(-)=abs(braket(-, 1))^2=1/2 +$ + +=== Example: $ket(psi)=(1+2i)/sqrt(7)ket(0)+(1-i)/sqrt(7)ket(1)$ +$ + P(0) & =abs((1+2i)/sqrt(7))^2=(1^2+2^2)/7=5/7 \ + P(1) & =abs((1-i)/sqrt(7))^2=(1^2+(-1)^2)/7=2/7 +$ +#tip[ Sum must be $1$. ] diff --git a/requirements.typ b/requirements.typ index 412f1b6..9ddeeb8 100644 --- a/requirements.typ +++ b/requirements.typ @@ -1,3 +1,4 @@ #import "@preview/fletcher:0.5.7" #import "@preview/physica:0.9.5" #import "@preview/quill:0.6.1" +#import "@preview/gentle-clues:1.2.0"