Contents
What can a quantum circuit do?
A quantum circuit is a computational routine consisting of coherent quantum operations on quantum data, such as qubits, and concurrent real-time classical computation. Any quantum program can be represented by a sequence of quantum circuits and non-concurrent classical computation.
What exactly is a quantum computer?
Quantum computers are machines that use the properties of quantum physics to store data and perform computations. In a quantum computer, the basic unit of memory is a quantum bit or qubit. Qubits are made using physical systems, such as the spin of an electron or the orientation of a photon.
Is it possible to simulate a quantum computer?
However, yes, you can make software simulations of a quantum computer using your average laptop/desktop. The exact “limit” will depend on the computer specifications. Since a quantum computer does not violate the Church-Turing thesis, in theory it is definitely possible to simulate a quantum computer using an ideal Turing machine.
How many qubits are needed for a quantum computer?
Both the memory requirements, and the time required to simulate an elementary circuit operation, grow exponentially with the number of qubits. A quantum computer of only 50 qubits is too large to be comprehensively simulated by our best classical computers 2, and has already been surpassed by Google’s 72 qubit Bristlecone QPU 3.
Which is the first open source quantum exact simulator?
We introduce QuEST, the Quantum Exact Simulation Toolkit, and compare it to ProjectQ, qHipster and a recent distributed implementation of Quantum++. QuEST is the first open source, hybrid multithreaded and distributed, GPU accelerated simulator of universal quantum circuits.
What kind of circuit can quest simulate?
QuEST is capable of simulating generic quantum circuits of general one and two-qubit gates and multi-qubit controlled gates, on pure and mixed states, represented as state-vectors and density matrices, and under the presence of decoherence.