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 lib 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)

Modules

ket.base	Base quantum programming classes.
ket.expv	Expected value calculation utilities.
ket.gates	Quantum gate definitions.
ket.lib	Quantum library.
ket.operations	Functions to manipulate quantum operations.
ket.quantumstate	Quantum state snapshot.