监管技术巨头：技术力量作为市场支配地位认定因素之再审视

如何有效规制技术巨头已然成为当前《反垄断法》修订的重要任务。技术力量虽然作为传统的市场支配地位认定要素,但长期以来呈现被虚置化的客观状态,致使技术巨头市场支配地位的认定难度增大,技术力量自身的传导效应被显著低估。数字技术对市场竞争的影响异于以往,其通过平台、数据、算法的数字市场三维结构框架影响生产与交易的全过程。技术与三维结构结合所形成的技术力量极为强大,超越了以控制价格为主的传统市场力量,结合社会与资本力量形成了更牢固的市场固化结构。在判断技术巨头的市场支配地位时,亟需发挥技术力量作为非价格型认定要素的重要作用。应当摒弃虚置技术力量作为市场支配地位认定要素的固有症结,提高技术力量在认定市场支配地位时所占权重,回归结构性视角,妥善防范技术巨头无序扩张。     

3D-Transmon与压电振子的量子耦合系统北大核心

微机械振子在量子信息领域有着重要的应用,可用作量子存储器、量子换能器等.鉴于三维传输子量子比特(3D-Transmon)优良的退相干特性以及AlN压电振子较高的谐振频率,我们利用微纳加工技术,在蓝宝石基片上成功制备了3D-Transmon与AlN压电振子的量子耦合系统.实际测量结果显示,在外加磁场偏置下,量子比特的跃迁频率可调范围为4.1~9.8 GHz,能量弛豫时间T1约为4.7μs,并且测量到了能级免交叉现象.这些结果为今后超导量子比特与微机械振子耦合系统的深入研究提供了重要参考.     

An easily-prepared impedance matched Josephson parametric amplifier

An impedance matched parametric amplifier (IMPA) with Josephson junctions is fabricated and characterized. A hybrid structure containing coplanar and strip structures is implemented to realize an impedance taper line and a plate capacitor in an LC nonlinear resonator based on Josephson junctions. The upper plate of the capacitor is isolated with SiN_x without grounding as well as the strips. Such easily-prepared designs greatly reduce the requirements for lithography alignment and precision, which makes the fabrication process more reliable. The experimental results show that in such IMPA a gain higher than 25 dB with a bandwidth of about 100 MHz can be obtained. This broadband amplifier operates close to the quantum limit. By adjusting the working point, a higher bandwidth of about 400 MHz can be obtained with a gain of about 17 dB.