Synopsis: Towards nuclear spin control

Optical tuning of resonant NMR frequencies of nuclear spins in a single quantum dot achieves spatial resolution below the size of the dot.
Synopsis figure
Credit: M. Makhonin et al., Phys. Rev. B (2010)

Nuclear spins in semiconductor quantum dots have very long relaxation and coherence times, both centrally important properties for the construction of future spintronic devices and quantum computers. Direct control of nuclear spins at the nanoscale by resonant techniques such as NMR is another highly desirable milestone for the realization of these devices. Cutting-edge optically detected NMR (ODNMR) techniques are currently able to control as few as 104 nuclei within a length scale of 100nm.

Now, in an article published in Physical Review B, Maxim Makhonin and collaborators from the University of Sheffield in the UK demonstrate a new ODNMR technique achieving two orders of magnitude improvement in resolution. Their idea is to use the strong localization of an electron confined in a semiconductor quantum dot to generate an effective magnetic field (Knight field) with strong gradients, which arise from the shape of the electron wave function. The proposed method exploits the inhomogeneities in the corresponding Knight shifts to selectively access, by appropriate resonant frequencies, small groups of nuclear spins located in different regions within the quantum dot. – Athanasios Chantis


More Features »


More Announcements »

Subject Areas


Previous Synopsis


Finer features

Read More »

Related Articles

Viewpoint: Squeezed Environment Boosts Engine Performance

Viewpoint: Squeezed Environment Boosts Engine Performance

A tiny engine can surpass the Carnot limit of efficiency when researchers engineer the thermal properties of the environment. Read More »

Synopsis: Transistor Breaks Law of Thermal Conductivity

Synopsis: Transistor Breaks Law of Thermal Conductivity

A single-electron transistor carries more heat than that predicted by the Wiedemann-Franz law linking thermal and electrical conductivities. Read More »

Synopsis: Two-Pulse X  Rays Probe Skyrmions

Synopsis: Two-Pulse X Rays Probe Skyrmions

A new x-ray spectroscopy technique can measure magnetic fluctuations in vortex-like structures called Skyrmions with nanosecond resolution. Read More »

More Articles