Atomic-scale imaging of a 27-nuclear-spin cluster using a quantum sensor

Abstract

Nuclear magnetic resonance (NMR) is a powerful method for determining the structure of molecules and proteins [1]. While conventional NMR requires averaging over large ensembles, recent progress with single-spin quantum sensors [2][3][4][5][6][7][8][9] has created the prospect of magnetic imaging of individual molecules [10][11][12][13]. As an initial step towards this goal, isolated nuclear spins and spin pairs have been mapped [14][15][16][17][18][19][20][21]. However, large clusters of interacting spins -such as found in molecules -result in highly complex spectra. Imaging these complex systems is an outstanding challenge due to the required high spectral resolution and efficient spatial reconstruction with sub-angstrom precision. Here we develop such atomic-scale imaging using a single nitrogen-vacancy (NV) centre as a quantum sensor, and demonstrate it on a model system of 27 coupled 13 C nuclear spins in a diamond. We present a new multidimensional spectroscopy method that isolates individual nuclearnuclear spin interactions with high spectral resolution (< 80 mHz) and high accuracy (2 mHz). We show that these interactions encode the composition and inter-connectivity of the cluster, and develop methods to extract the 3D structure of the cluster with sub-angstrom resolution. Our results demonstrate a key capability towards magnetic imaging of individual molecules and other complex spin systems [9][10][11][12][13].The nitrogen-vacancy (NV) centre in diamond has emerged as a powerful quantum sensor [2-13, 22, 23]. The NV electron spin provides long coherence times [5, 6,20] and high-contrast optical readout [5,24,25], enabling high sensitivity over a large range of temperatures [5, 6,20,25,26]. Pioneering experiments with near-surface NV centers have demonstrated spectroscopy of small ensembles of nuclear spins in nano-scale volumes [2, 3,[5][6][7][8], and electron-spin labelled proteins [4]. Furthermore, single nuclear spin sensitivity has been demonstrated and isolated individual nuclear spins and spin pairs have been mapped [14][15][16][17][18][19][20][21]. Together, these results have established the NV center as a promising platform * T.H.Taminiau@TUDelft.nl for magnetic imaging of complex spin systems and single molecules [10][11][12][13].In this work, we realise a key ability towards that goal: the 3D imaging of large nuclear-spin structures with atomic resolution. The main idea of our method is to obtain structural information by accessing the couplings between individual nuclear spins. The key open challenges are: (1) to realize high spectral resolution so that small couplings can be accessed, (2) to isolate such couplings from complex spectra, and (3) to transform the revealed connectivity into the 3D spatial structure with sub-angstrom precision.The basic elements of our experiment are illustrated in Fig. 1a. We consider a cluster of 13 C nuclear spins in the vicinity of a single NV centre in diamond at 4 K. This cluster provides a model system for the magnetic imaging of single molecules and spin ...

Algorithmic decomposition for efficient multiple nuclear spin detection in diamond

“…The reported hyperfine values of spin 5, 7, 8 and 9 show large deviations from all values in ref. 23, and spin 6 has a consistent match in ref. 23.…”

“…Spin 3 and 13 have their consistent match among the values of ref. 23, even though their B values were below the confidence threshold. Spin 5-9 show dip periods similar to the spin bath and overlap with each other as shown in Fig.…”

“…1a. Owing to the long coherence times of these nuclear spins 18 , detecting and manipulating naturally trapped nuclear spins in diamond through NV centers is emerging as a promising pathway to enable controlled quantum systems such as spin qubit registers [19][20][21][22][23][24] , quantum networks 25,26 , quantum simulation platforms 18,27 , and quantum memories [28][29][30] . Because naturally occurring 13 C nuclear spins are randomly located around an NV center electron spin 31,32 , the efficient and automatic characterization of hyperfine interactions of individual nuclear spins is a prerequisite step towards building scalable quantum systems based on this platform.…”

Construction and operation of a tabletop system for nanoscale magnetometry with single nitrogen-vacancy centers in diamond

“…The use of the single-NV quantum sensor significantly reduces the required volume of analyte for nuclear magnetic resonance (NMR), ultimately down to the single molecular level. Recent demonstrations toward this ambitious goal include detection of single protons, 17 spectroscopy of single proteins, 18 sub-hertz spectral resolution, [19][20][21][22][23] spectroscopy and tracking of single nuclear spins via weak measurements, 24,25 determination of the positions of single nuclear spins, [26][27][28][29][30] and so forth. Remarkably, many of them have been realized at room temperature.…”

Extending qubit coherence by adaptive quantum environment learning

“…Individual spins are an established platform for developing solid-state quantum technologies for improved metrology [1][2][3][4][5][6][7][8][9][10][11], communication [12,13] and information processing [14][15][16][17]. All quantum applications rely on the capability to preserve the coherence of quantum states.…”