arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1606.04697cond-mat.mes-hall
收藏

硅中受主自旋的量子计算

Quantum Computing with Acceptor Spins in Silicon

Joe Salfi, Mengyang Tong, Sven Rogge, Dimitrie Culcer

摘要:

Si/SiO2界面附近的硼受体的状态结合两个低能Kramers对,具有编码量子信息的特殊性质,并且借助于应变,可以设计基于重空穴和轻空穴的自旋量子比特。而最近推出的轻孔自旋量子比特[物理评论Lett. 116,246801(2016)],在这里,我们提出的分析和数值结果证明,一个重孔自旋量子比特可以可靠地初始化,旋转和纠缠的电气手段单独。这是由于强Rashba样的自旋轨道相互作用项使界面反转不对称。单量子位旋转依赖于电偶极自旋共振(EDSR),这是强烈增强的界面诱导的自旋轨道项。纠缠可以通过库仑交换、耦合到谐振器或自旋-轨道诱导的偶极-偶极相互作用来实现。通过分析量子比特对电荷噪声的敏感性,我们证明了界面诱导的自旋轨道项负责作为顶栅电场的函数的失相时间T2* 中的最佳点,其接近EDSR强度的最大值,其中EDSR门具有高保真度。我们表明,这两个量子位可以使用相同的起始哈密顿量来描述,并通过比较它们的性质,我们表明,体和界面诱导的自旋轨道项的复杂相互作用允许高度的电气控制,并使受体的潜在候选人可扩展的量子计算在Si中。

英文摘要:

The states of a boron acceptor near a Si/SiO2 interface, which bind two low-energy Kramers pairs, have exceptional properties for encoding quantum information and, with the aid of strain, both heavy hole and light hole-based spin qubits can be designed. Whereas a light-hole spin qubit was introduced recently [Phys. Rev. Lett. 116, 246801 (2016)], here we present analytical and numerical results proving that a heavy-hole spin qubit can be reliably initialised, rotated and entangled by electrical means alone. This is due to strong Rashba-like spin-orbit interaction terms enabled by the interface inversion asymmetry. Single qubit rotations rely on electric-dipole spin resonance (EDSR), which is strongly enhanced by interface-induced spin-orbit terms. Entanglement can be accomplished by Coulomb exchange, coupling to a resonator, or spin-orbit induced dipole-dipole interactions. By analysing the qubit sensitivity to charge noise, we demonstrate that interface-induced spin-orbit terms are responsible for sweet spots in the dephasing time T2* as a function of the top gate electric field, which are close to maxima in the EDSR strength, where the EDSR gate has high fidelity. We show that both qubits can be described using the same starting Hamiltonian, and by comparing their properties we show that the complex interplay of bulk and interface-induced spin-orbit terms allows a high degree of electrical control and makes acceptors potential candidates for scalable quantum computation in Si.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑