Fast Multiqubit Gates through Simultaneous Two-Qubit Gates
Artikel i vetenskaplig tidskrift, 2021

Near-term quantum computers are limited by the decoherence of qubits to only being able to run low-depth quantum circuits with acceptable fidelity. This severely restricts what quantum algorithms can be compiled and implemented on such devices. One way to overcome these limitations is to expand the available gate set from single- and two-qubit gates to multiqubit gates, which entangle three or more qubits in a single step. Here, we show that such multiqubit gates can be realized by the simultaneous application of multiple two-qubit gates to a group of qubits where at least one qubit is involved in two or more of the two-qubit gates. Multiqubit gates implemented in this way are as fast as, or sometimes even faster than, the constituent two-qubit gates. Furthermore, these multiqubit gates do not require any modification of the quantum processor, but are ready to be used in current quantum-computing platforms. We demonstrate this idea for two specific cases: simultaneous controlled-Z gates and simultaneous iswap gates. We show how the resulting multiqubit gates relate to other well-known multiqubit gates and demonstrate through numerical simulations that they would work well in available quantum hardware, reaching gate fidelities well above 99%. We also present schemes for using these simultaneous two-qubit gates to swiftly create large entangled states like Dicke and Greenberger-Horne-Zeilinger states.

Författare

Xiu Gu

Tencent

Chalmers, Mikroteknologi och nanovetenskap, Tillämpad kvantfysik

Jorge Fernández-Pendás

Chalmers, Mikroteknologi och nanovetenskap, Tillämpad kvantfysik

Pontus Vikstål

Chalmers, Mikroteknologi och nanovetenskap, Tillämpad kvantfysik

Tahereh Abad

Chalmers, Mikroteknologi och nanovetenskap, Tillämpad kvantfysik

Christopher Warren

Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi

Andreas Bengtsson

Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi

Giovanna Tancredi

Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi

Vitaly Shumeiko

Chalmers, Mikroteknologi och nanovetenskap, Tillämpad kvantfysik

Jonas Bylander

Chalmers, Mikroteknologi och nanovetenskap, Kvantteknologi

Göran Johansson

Chalmers, Mikroteknologi och nanovetenskap, Tillämpad kvantfysik

Anton Frisk Kockum

Chalmers, Mikroteknologi och nanovetenskap, Tillämpad kvantfysik

PRX Quantum

26913399 (eISSN)

Vol. 2 4 A202

Ämneskategorier

Datorteknik

Annan elektroteknik och elektronik

Den kondenserade materiens fysik

DOI

10.1103/PRXQuantum.2.040348

Mer information

Senast uppdaterat

2024-01-03