Miniaturizing Transmon Qubits Using van der Waals Materials

Abstract

Quantum computers can potentially achieve an exponential speedup versus classical computers on certain computational tasks, recently demonstrated in superconducting qubit processors. However, the capacitor electrodes that comprise these qubits must be large in order to avoid lossy dielectrics. This tactic hinders scaling by increasing parasitic coupling among circuit components, degrading individual qubit addressability, and limiting the spatial density of qubits. Here, we take advantage of the unique properties of van der Waals (vdW) materials to reduce the qubit area by >1000 times while preserving the capacitance while maintaining quantum coherence. Our qubits combine conventional aluminum-based Josephson junctions with parallel-plate capacitors composed of crystalline layers of superconducting niobium diselenide and insulating hexagonal boron nitride. We measure a vdW transmon T 1 relaxation time of 1.06 μs, demonstrating a path to achieve high-qubit-density quantum processors with long coherence times, and the broad utility of layered heterostructures in low-loss, high-coherence quantum devices.

Percolating Superconductivity in Air‐Stable Organic‐Ion Intercalated MoS2

“…Moreover, these layered superconductors are emerging as a crucial material platform for quantum computing [ 7,8 ] as they offer the possibility to dramatically scale down the footprint of superconductive qubits when interfaced with ultrathin 2D dielectrics. [ 9,10 ]…”

“…superconductive qubits when interfaced with ultrathin 2D dielectrics. [9,10] While superconductivity naturally occurs in some layered compounds such as NbSe 2 [2,3,11] and 2H-TaS 2 , [4] charge carrier doping leading to electron densities in the order of 10 14 carriers cm −2 per layer can drive other vdW materials into a superconducting state. For instance, exfoliated flakes of MoS 2 , which is a semiconductor in its pristine state, [12,13] display a superconductive transition when exposed to the extreme electric fields generated by ionic liquid gating.…”

A gate-tunable graphene Josephson parametric amplifier

“…three wave mixing terms are present even at zero DC current bias and could be directly used. Together with the recent developments regarding qubits [42], bolometers [43,44] and the use of van der Waals materials in superconducting quantum circuits [45][46][47], the demonstration we report here for quantum limited amplifiers position semiconductor based Josephson junctions as key elements for future integrated superconducting quantum circuits.…”

Inhibition of chemically and mechanically activated Piezo1 channels as a mechanism for ameliorating atherosclerosis with salvianolic acid B

“…Papers including ours pointed towards a strong interplay between plasma membrane tension gradients, curvature, cytoskeleton or focal adhesions, associating with Piezo1 channels. Thus, focal adhesion molecules and actin cytoskeleton such as ZO-1, occludin, VE-cadherin and F-actin may functionally coordinate with Piezo1 (Antony et al, 2021;Jiang et al, 2021;Li et al, 2014). Piezo1 channels interacted with the fluid shear-stress-induced phosphorylation of Src kinases, PECAM-1 and VEGFR2 (Wang et al, 2016).…”