Ultrafast coherent manipulation of trions in site-controlled nanowire quantum dots

Abstract

†These authors contributed equally to this workPhysical implementations of large-scale quantum processors based on solid-state platforms benefit from realizations of quantum bits positioned in regular arrays. Self-assembled quantum dots are well-established as promising candidates for quantum optics and quantum information processing, but they are randomly positioned. Site-controlled quantum dots, on the other hand, are grown in pre-defined locations, but have not yet been sufficiently developed to be used as a platform for quantum information processing. In this letter we demonstrate all-optical ultrafast complete coherent control of a qubit formed by the single-spin/trion states of a charged sitecontrolled nanowire quantum dot. Our results show that site-controlled quantum dots in nanowires are promising hosts of charged-exciton qubits, and that these qubits can be cleanly manipulated in the same fashion as has been demonstrated in randomly-positioned quantum dot samples. Our findings suggest that many of the related excitonic qubit experiments that have been performed over the past 15 years may work well in the more scalable site-controlled systems, making them very promising for the realization of quantum hardware.

Complete coherent control of silicon vacancies in diamond nanopillars containing single defect centers

“…After setting the amplitude of both pulses, the fine interpulse delay is scanned over 10 fs while recording the photon counts from the detection channel. The Ramsey-type interference experiment is repeated for all accessible pulse powers, and the resulting photon count map as a function of interpulse fine delay and individual pulse power is provided in Figure 4b, showing the typical multi-lobed structure expected of complete coherent control of resonantly driven qubits 1 . Again, emitter spectral stability and setup phase stability over several hours of acquisition time were necessary to produce the highquality SU(2) control results shown in Figure 4b.…”

“…Deterministic positioning of individual quantum emitters with nearly identical properties is an outstanding challenge towards the creation of large scale quantum hardware. Recent technological leaps have enabled the development of high quality site-controlled quantum dots that have attracted a strong interest for their potential use as building blocks in scalable quantum hardware [1][2][3] , yet the inhomogeneous broadening of such emitters still imposes limitations towards large scale integration. An alternative system that has arisen as a promising candidate for scalable qubits is the nitrogen vacancy (NV -) centers in diamond, due to its excellent spin properties under ambient conditions [4][5][6] and potential for on-demand positioning 7,8 .…”

Resonant driving of a single photon emitter embedded in a mechanical oscillator

“…A quantum emitter in a nanowire has potential for various quantum applications. On the one hand, dielectric nanowires are used as waveguides to realize high-fidelity single-photon sources in quantum optics 14 , 15 , 31 , 32 . In this context, the strain coupling represents an additional dephasing channel with potential impact on the photon indistinguishability.…”

Creation of regular arrays of faceted AlN nanostructures via a combined top-down, bottom-up approach

“…Single photon emission (SPE) from III-N site-controlled quantum dots has been demonstrated to operate above room temperature [16]. Arrays of quantum dots which offer spatial, shape and size determination leading to identical properties are particularly suitable for quantum information processing (QIP) applications [17,18,16]. Previously, SPE from GaN quantum dots at [19] and above room temperature [16] was achieved using GaN nanorods created via selective area growth (SAG).…”