10-Qubit Entanglement and Parallel Logic Operations with a Superconducting Circuit

Abstract

Here we report on the production and tomography of genuinely entangled Greenberger-Horne-Zeilinger states with up to ten qubits connecting to a bus resonator in a superconducting circuit, where the resonator-mediated qubit-qubit interactions are used to controllably entangle multiple qubits and to operate on different pairs of qubits in parallel. The resulting 10-qubit density matrix is probed by quantum state tomography, with a fidelity of 0.668±0.025. Our results demonstrate the largest entanglement created so far in solid-state architectures and pave the way to large-scale quantum computation.

Gate-error analysis in simulations of quantum computers with transmon qubits

“…In theory, such a device can solve certain problems, such as factoring, exponentially faster than classical digital computers. The leading technological prototypes are based on superconducting transmon qubits containing on the order of 10 qubits [1][2][3][4]. IBM provides public access to such a quantum processor through the IBM Quantum Experience (IBMQX) [5].…”

Transferring entangled states of photonic cat-state qubits in circuit QED

“…Based on circuit QED, many proposals have been presented for implementing quantum state transfer between SC qubits [1,[13][14][15], quantum logic gates of SC qubits [16][17][18][19][20][21], and entanglement in SC qubits [22][23][24][25][26][27][28]. By using SC qubits, the experimental demonstrations of single-qubit gates [29,30], two-qubit gates [31,32], three-qubit gates [33,34], 10-qubit entanglement [35], 12-qubit entanglement [36], 18-qubit entanglement [37], and 20-qubit Schrödinger cat states [37] have been reported. Moreover, quantum teleportation between two distant SC qubits [38], quantum state transfer in a SC qubit chain [39], entanglement swapping in superconducting circuit [40], and quantum walks in a 12-qubit superconducting processor [41] have been realized in experiments.…”

Quantum Computer Simulates Excited States of Molecule

“…Our work shows how errors can be suppressed via additional measurements, potentially offering an alternative to more advanced error-correction techniques, which are typically difficult to implement and require large resource overhead. These methods can be directly transferred to other systems, such as planar superconducting platforms and ion traps, where significant numbers of qubits can be routinely controlled and read out [1,2,[24][25][26], potentially paving the way for larger more complex quantum simulations in the near future.…”