Ket API

Ket Quantum Programming Platform.

Ket is a comprehensive library designed for quantum programming, providing essential functions and classes to build quantum algorithms and applications. It facilitates the manipulation and storage of quantum states, measurement operations, and the computation of expected values.

Explore the documentation of individual submodules for in-depth information and more practical code examples.

All the functionality from the submodules is conveniently accessible within the ket namespace. Except for the qulib module.

Examples

• Grover algorithm

from math import sqrt, pi
import ket
def grover(size: int, oracle) -> int:
    p = ket.Process(simulator="dense", num_qubits=size)
    s = ket.H(p.alloc(size))
    steps = int((pi / 4) * sqrt(2**size))
    for _ in range(steps):
        oracle(s)
        with ket.around(ket.H, s):
            ket.phase_oracle(0, s)
    return ket.measure(s).value

• Quantum teleportation protocol

import ket
def teleport(alice_msg, alice_aux, bob_aux):
    ket.ctrl(alice_msg, ket.X)(alice_aux)
    ket.H(alice_msg)
    m0 = ket.measure(alice_msg)
    m1 = ket.measure(alice_aux)
    if m1.value == 1:
        ket.X(bob_aux)
    if m0.value == 1:
        ket.Z(bob_aux)
    return bob_aux
def bell(qubits):
    return ket.ctrl(ket.H(qubits[0]), ket.X)(qubits[1])
def message(qubit):
    ket.H(alice)
    ket.Z(alice)
p = ket.Process()
alice = p.alloc()  # alice = |0⟩
message(alice)     # alice = |–⟩
bob = teleport(alice, *bell(p.alloc(2)))  # bob  <- alice
ket.H(bob)         # bob   = |1⟩
bob_m = ket.measure(bob)
print("Expected measure 1, result =", bob_m.value)
# Expected measure 1, result = 1

Submodules

amazon	AmazonBraket Interface for Ket
base	Base classes for quantum programming.
expv	Expected value calculation utilities.
fermion	Fermionic operators and utilities.
gates	Quantum gate definitions.
ibm	Module providing functionality to interact with IBM Quantum and IBM Cloud devices.
measurement	Quantum measurement result classes.
npsim	Live Execution Simulator Based on NumPy
operations	Functions to manipulate quantum operations.
qint	Quantum integer and fixed-point real number data structures.
quantumstate	Quantum state snapshot representation and visualization.
qulib	Quantum library.

ket_version() → list[str]

Return the version strings of all Ket platform components.

Queries the underlying Rust libraries (libket and kbw) for their build information and combines it with the Python package version.

Returns:

• "Ket v<version>", the Python package version.

• A build-info string from the libket Rust runtime library.

• A build-info string from the kbw quantum simulator library.

Return type:

A list containing three version strings in the following order