• Physics 15, s130
A brand new sort of superconducting qubit might clear up a “crowding” drawback that hinders the event of superconducting quantum computer systems with giant numbers of qubits.
In terms of superconducting quantum processors, the go-to qubit is the “transmon,” which has a low sensitivity to noise. Processors with greater than 50 transmons are available, and a system with 127 transmons was lately demonstrated. Regardless of these achievements, transmons have operational points that might hinder techniques containing bigger numbers of those qubits. Now Baleegh Abdo and colleagues at IBM Analysis Middle in New York have developed a brand new superconducting qubit that solves one among these issues . The brand new qubit might doubtlessly exchange transmons within the subsequent set of superconducting quantum processors.
The problem that the workforce addresses is the “frequency-collision” drawback. Up to now, transmon qubits operated at a hard and fast frequency, that means that in circuits containing giant numbers of them, gate errors might happen due to overlap within the qubits’ excitation energies. Having neighboring qubits with barely totally different operational frequencies can clear up the difficulty. However earlier tunable transmons have been extremely inclined to noise, comparable to magnetic-flux noise, which might trigger speedy dephasing of the transmons and gate errors.
Abdo and colleagues get across the situation by making a frequency-tunable qubit that doesn’t endure from dephasing. Like transmons, their “weakly tunable qubit” (WTQ) operates utilizing Josephson junctions, however it comprises three junctions reasonably than one. Every junction has barely totally different properties, which the workforce exploits to tune every qubit’s frequency by just a few tenths of a p.c. The tunability is giant sufficient to keep away from frequency collisions but sufficiently small to restrict their susceptibility to noise. The researchers says that their use of Josephson junctions ought to help within the adoption of WTQs, as they’re made utilizing the identical processes as transmons.
Katherine Wright is the Deputy Editor of Physics Journal.
- J. M. Chávez-Garcia et al., “Weakly flux-tunable superconducting qubit,” Phys. Rev. Appl. 18, 034057 (2022).