qit.gate.copydot

qit.gate.copydot(n_in, n_out, d=2)

Copy dot.

A copy dot is a tensor that copies any computational basis state, in the sense that connecting :math`ket{k}` to any of its legs breaks it up into $n_{\text{in}}+n_{\text{out}}-1$ unconnected copies of :math`ket{k}` and :math`bra{k}`.

$${\mathrm{COPY}}^{n_{\text{in}}\to n_{\text{out}}}=\sum _{k=0}^{d-1}|\underset{n_{\text{out}}}{\underbrace{k\cdots k}}⟩⟨\underset{n_{\text{in}}}{\underbrace{k\cdots k}}|.$$

Parameters

• n_in (int) – number of input legs

• n_out (int) – number of ouput legs

• d (int) – leg dimension

Returns

copy dot

Return type

Lmap

See [9]