Struct PauliString 

#[repr(C)]
pub struct PauliString<const W: usize> {
    pub x: [u64; W],
    pub z: [u64; W],
}

A Pauli operator on up to 64·W qubits, W being the number of 64-bit words per x/z part.

Pick the smallest W that fits; the Python bindings monomorphize W ∈ {1, 2, 4, 8, 16}. The phase of a product is not stored: Self::mul_assign returns it as a Phase for the caller to fold into a coefficient. Y is the key (x=1, z=1) with no phase factor.

Fields

x: [u64; W]

X-part bitmask: bit q set iff qubit q is X or Y.

z: [u64; W]

Z-part bitmask: bit q set iff qubit q is Z or Y.

Implementations

impl<const W: usize> PauliString<W>

pub const fn identity() -> Self

Identity Pauli string (all qubits I).

pub fn x(qubit: usize) -> Self

Single-qubit X Pauli on qubit.

Panics

Panics in debug builds if qubit >= 64 · W.

pub fn y(qubit: usize) -> Self

Single-qubit Y = (x=1, z=1) on qubit; the i in Y = i·X·Z is the caller’s concern.

Panics

Panics in debug builds if qubit >= 64 · W.

pub fn z(qubit: usize) -> Self

Single-qubit Z Pauli on qubit.

Panics

Panics in debug builds if qubit >= 64 · W.

pub fn weight(&self) -> u32

Number of non-identity qubits.

pub fn mul_assign(&mut self, other: &Self) -> Phase

Multiply self * other in place, returning the phase i^k such that the true product is phase · self.

pub fn product(self, other: &Self) -> (Self, Phase)

Value-returning multiply: (self * other, phase).

pub fn is_within(&self, num_qubits: usize) -> bool

true iff every set bit lies on a qubit index < num_qubits.

Panics

Panics in debug builds if num_qubits > 64 · W.

pub fn commutes_with(&self, other: &Self) -> bool

true iff self and other commute as Pauli operators.

pub fn commutator(self, other: &Self) -> (Self, Complex64)

Commutator [self, other] = self·other − other·self, as (product, coefficient).

The coefficient is 2·i^k when the strings anticommute and exactly 0 when they commute; the returned string is Self::product’s result either way.

pub fn anticommutator(self, other: &Self) -> (Self, Complex64)

Anticommutator {self, other} = self·other + other·self, as (product, coefficient).

The coefficient is 2·i^k when the strings commute and exactly 0 when they anticommute.

Trait Implementations

impl<const W: usize> Clone for PauliString<W>

fn clone(&self) -> PauliString<W>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<const W: usize> Debug for PauliString<W>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<const W: usize> Default for PauliString<W>

fn default() -> Self

Returns the “default value” for a type.

impl<const W: usize> Hash for PauliString<W>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<const W: usize> Ord for PauliString<W>

fn cmp(&self, other: &PauliString<W>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<const W: usize> PartialEq for PauliString<W>

fn eq(&self, other: &PauliString<W>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<const W: usize> PartialOrd for PauliString<W>

fn partial_cmp(&self, other: &PauliString<W>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<const W: usize> Copy for PauliString<W>

impl<const W: usize> Eq for PauliString<W>

impl<const W: usize> StructuralPartialEq for PauliString<W>