Chapter 1

The problems in this chapter are focused on qubit states and simple untiary operators.

Background Material

Any two-state quantum system can be used as a quantum bit (qubit); the corresponding quantum computing version of a bit but with the addition that it can be in a superposition state.

The vector space with defined inner product (i.e. Hilbert space) that describes that state of a qubit is C2\mathbb{C}^2.

The Dirac notation to denote an orthonormal qubit basis set is given as {0,1} \{\ket{0},\ket{1}\} with the inner product defined as 00=11=1 \braket{0|0}= \braket{1|1} = 1 and 01=10=0 \braket{0|1} = \braket{1|0} = 0 .

A superposition state can be written as:

ψ=α0+β1 \ket{\psi} = \alpha \ket{0} + \beta \ket{1}

with the conditions that the inner product ψψ=αα00+ββ11=1 \braket{\psi|\psi} = \alpha^{*} \alpha \braket{0|0} + \beta^{*} \beta \braket{1|1} = 1

Examples of basis sets are:

0=(10),0=(01) \ket{0} = \begin{pmatrix} 1 \\ 0 \end{pmatrix}, \hskip{5mm} \ket{0} = \begin{pmatrix} 0 \\ 1 \end{pmatrix} 0=+=12(11),0==12(11) \ket{0} = \ket{+} = \frac{1}{\sqrt{2}} \begin{pmatrix} 1 \\ 1 \end{pmatrix}, \hskip{5mm} \ket{0} = \ket{-} = \frac{1}{\sqrt{2}} \begin{pmatrix} 1 \\ -1 \end{pmatrix}

Problems

Programming Problems