Superconducting qubits, a specific sort of quantum processing stage that utilizes superconducting circuits, contain inductors and capacitors. Very much like in a radio or other electronic gadget, these capacitors store the electric field energy. A capacitor is frequently fabricated like a sandwich, with metal plates on one or the other side of a protecting, or dielectric, material.
In any case, not at all like a radio, superconducting quantum PCs work at super-cool temperatures – under 0.02 degrees above outright zero (- 273.15 degrees Celsius) – and have exceptionally high-recurrence electric fields, like the present cellphones. Most protecting materials that work in this system have deserts. While not unfavorable to most old style applications, when quantum-rational data goes through the dielectric layer, it might get lost or assimilated in some irregular manner.
“Most normal dielectrics utilized for incorporated circuits, like silicon oxides or silicon nitrides, have many deformities, bringing about quality elements around 500 to 1,000. This is essentially excessively lossy for quantum figuring applications,” Oliver says.
To get around this, customary qubit capacitors are more similar to open-confronted sandwiches, with no top plate and a vacuum sitting over the base plate to go about as the protecting layer.
“The value one pays is that the plates are a lot greater in light of the fact that you weaken the electric field and utilize a lot bigger layer for the vacuum,” Wang says. “The size of every individual qubit will be a lot bigger than if you can contain everything in a little gadget. Furthermore the other issue is, the point at which you have two qubits close to one another, and each qubit has its own electric field open to the free space, there may be some undesirable talk between them, which can make it hard to control only one qubit. One couldn’t imagine anything better than to return to the exceptionally unique thought of a capacitor, which is only two electric plates with an extremely spotless encasing sandwiched in the middle.”
In this way, that is what these analysts did.
They thought hexagonal boron nitride, which is from a family known as van der Waals materials (additionally called 2D materials), would be a decent contender to fabricate a capacitor. This remarkable material can be weakened to one layer of particles that is translucent in structure and doesn’t contain deserts. Scientists can then stack those slight layers in wanted setups.
To test hexagonal boron nitride, they ran trials to portray how clean the material is while interfacing with a high-recurrence electric field at ultracold temperatures, and observed that tiny energy is lost when it goes through the material.
“A significant part of the past work describing hBN (hexagonal boron nitride) was performed at or close to zero recurrence utilizing DC transport estimations. In any case, qubits work in the gigahertz system. It’s incredible to see that hBN capacitors have quality elements surpassing 100,000 at these frequencies, among the most noteworthy Qs I have seen for lithographically characterized, incorporated equal plate capacitors,” Oliver says.