标题： 平面二维量子比特中射频表面损耗的分析 显示英文标题

标题： Analysis of RF Surface Loss in a Planar 2D Qubit

摘要： 约瑟夫森结和并联电容形成一个transmon量子比特，这是现代量子计算平台的核心。 对于可靠的量子计算，量子比特能够保持量子态叠加的时间长短非常重要，这由退相干时间（T1）决定。 量子比特的退相干时间有效设定了可用量子信息的“寿命”，决定了在出现错误和信息丢失之前可以进行多长时间的量子计算。 transmon量子比特中存在几种退相干来源，但通常认为主要原因是超导体表面形成的自然氧化层中的介电损耗。 在本文中，我们对不同transmon量子比特设计的平面超导天线中的微波表面损耗进行了数值研究。 提出了一种估计纳米尺度超薄薄膜中能量参与比的渐近方法，并给出了根据表面氧化物的电气特性以及量子比特与基板材料界面的可实现最小射频损耗的极限估计。 显示英文摘要

摘要： The Josephson junction and shunt capacitor form a transmon qubit, which is the cornerstone of modern quantum computing platforms. For reliable quantum computing, it is important how long a qubit can remain in a superposition of quantum states, which is determined by the coherence time (T1). The coherence time of a qubit effectively sets the "lifetime" of usable quantum information, determining how long quantum computations can be performed before errors occur and information is lost. There are several sources of decoherence in transmon qubits, but the predominant one is generally considered to be dielectric losses in the natural oxide layer formed on the surface of the superconductor. In this paper, we present a numerical study of microwave surface losses in planar superconducting antennas of different transmon qubit designs. An asymptotic method for estimating the energy participation ratio in ultrathin films of nanometer scales is proposed, and estimates are given for the limits of achievable minimum RF losses depending on the electrical properties of the surface oxide and the interface of the qubit with the substrate material.