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Spin defects in foils of hexagonal boron nitride are an attractive platform for magnetic field imaging, since the probe can be placed in close proximity to the target. However, as a III-V material the electron spin coherence is limited by the nuclear spin environment, with spin echo coherence times of ∽100 ns at room temperature accessible magnetic fields. We use a strong continuous microwave drive with a modulation in order to stabilize a Rabi oscillation, extending the coherence time up to ∽ 4μs, which is close to the 10 μs electron spin lifetime in our sample. We then define a protected qubit basis, and show full control of the protected qubit. The coherence times of a superposition of the protected qubit can be as high as 0.8 μs. This work establishes that boron vacancies in hexagonal boron nitride can have electron spin coherence times that are competitive with typical nitrogen vacancy centres in small nanodiamonds under ambient conditions. Spin defects in 2D hBN are promising for magnetic field sensing but suffer from short spin coherence times. Here the authors extend the coherence time for an ensemble of spins in hBN to 4 microseconds by using a continuous microwave drive and demonstrate qubit control in a protected spin space.

By sequentially recording the phase of an AC signal relative to an external clock, quantum heterodyne schemes have recorded MHz and GHz signals with Fourier-limited precision. However, in systems with large inhomogeneous broadening, existing heterodyne protocols provide limited protection of the spin coherence, impacting amplitude sensitivity. Here, we use a continuous microwave scheme that extends spin coherence towards the effective T 2 ≈ 1 2 T 1 limit and resolves the frequency, amplitude and phase of MHz to GHz magnetic fields. In an ensemble of boron vacancies in hexagonal boron nitride the scheme achieves an amplitude sensitivity of η ≈ 3 − 5 μ T / Hz and phase sensitivity of η ϕ ≈ 0.076 rads / Hz . We demonstrate that the scheme is compatible with quantum heterodyne detection, recording a GHz signal with a resolution  < 1 Hz and SNR of 235 over a 10 s measurement. Achieving this performance in a two-dimensional material platform could have broad applications in probing nanoscale condensed matter systems. Spin defects in hexagonal boron nitride are a promising platform for nanoscale magnetometry, however inhomogeneous noise degrades performance. C.J. Patrickson et al. use continuous dynamical decoupling to mitigate this noise, and to detect phase, amplitude and frequency of MHz - GHz fields.

Carlos López-Otín and colleagues report recurrent mutations in POT1 in chronic lymphocytic leukemia. This is the first member of the telomeric shelterin complex reported to be mutated in human cancer. Chronic lymphocytic leukemia (CLL) is the most frequent leukemia in adults 1 , 2 , 3 . We have analyzed exome sequencing data from 127 individuals with CLL and Sanger sequencing data from 214 additional affected individuals, identifying recurrent somatic mutations in POT1 (encoding protection of telomeres 1) in 3.5% of the cases, with the frequency reaching 9% when only individuals without IGHV @ mutations were considered. POT1 encodes a component of the shelterin complex and is the first member of this telomeric structure found to be mutated in human cancer. Somatic mutation of POT1 primarily occurs in gene regions encoding the two oligonucleotide-/oligosaccharide-binding (OB) folds and affects key residues required to bind telomeric DNA. POT1 -mutated CLL cells have numerous telomeric and chromosomal abnormalities that suggest that POT1 mutations favor the acquisition of the malignant features of CLL cells. The identification of POT1 as a new frequently mutated gene in CLL may facilitate novel approaches for the clinical management of this disease.

Mitochondria are dynamic subcellular organelles that convert nutrient intermediates into readily available energy equivalents. Optimal mitochondrial function is ensured by a highly evolved quality control system, coordinated by protein machinery that regulates a process of continual fusion and fission. In this work, we provide in vivo evidence that the ATP‐independent metalloprotease OMA1 plays an essential role in the proteolytic inactivation of the dynamin‐related GTPase OPA1 (optic atrophy 1). We also show that OMA1 deficiency causes a profound perturbation of the mitochondrial fusion–fission equilibrium that has important implications for metabolic homeostasis. Thus, ablation of OMA1 in mice results in marked transcriptional changes in genes of lipid and glucose metabolic pathways and substantial alterations in circulating blood parameters. Additionally, Oma1 ‐mutant mice exhibit an increase in body weight due to increased adipose mass, hepatic steatosis, decreased energy expenditure and impaired thermogenenesis. These alterations are especially significant under metabolic stress conditions, indicating that an intact OMA1‐OPA1 system is essential for developing the appropriate adaptive response to different metabolic stressors such as a high‐fat diet or cold‐shock. This study provides the first description of an unexpected role in energy metabolism for the metalloprotease OMA1 and reinforces the importance of mitochondrial quality control for normal metabolic function. The metalloprotease OMA1 is involved in the proteolytic inactivation of the dynaminrelated GTPase OPA1, a key regulator of mitochondrial dynamics. OMA1 knockout mice indicate that mitochondrial quality control and dynamics impact energy metabolism, in particular under metabolic stress.

Quantum sensing based on solid-state spin defects provides a uniquely versatile platform for nanoscale magnetometry under diverse environmental conditions. Operation of most sensors used to-date is based on projective measurement along a single axis combined with computational extrapolation. Here, we show that an individually addressable carbon-related spin defect in hexagonal boron nitride is a multi-axis nanoscale sensor with large dynamic range. For this spin-1 system, we demonstrate how its spin-dependent photodynamics give rise to three optically detected spin resonances that show up to 90% contrast and are not quenched under off-axis magnetic field exceeding 100 mT, enabling μ T / Hz − 1 / 2 sensitivity. Finally, we show how this system can be used to unambiguously determine the three components of a target magnetic field via the use of two bias fields. Alongside these features, the room-temperature operation and the nanometer-scale proximity enabled by the van der Waals host material further consolidate this system as a promising quantum sensing platform. Defects in materials can be used to detect magnetic fields at the nanoscale. Here the authors show that a carbon-related defect in hexagonal boron nitride acts as a robust nanoscale sensor capable of vectorial magnetic field detection.

Aging is a multifactorial process that affects most of the biological functions of the organism and increases susceptibility to disease and death. Recent studies with animal models of accelerated aging have unveiled some mechanisms that also operate in physiological aging. However, little is known about the role of microRNAs (miRNAs) in this process. To address this question, we have analysed miRNA levels in Zmpste24 ‐deficient mice, a model of Hutchinson–Gilford progeria syndrome. We have found that expression of the miR‐29 family of miRNAs is markedly upregulated in Zmpste24 −/− progeroid mice as well as during normal aging in mouse. Functional analysis revealed that this transcriptional activation of miR‐29 is triggered in response to DNA damage and occurs in a p53‐dependent manner since p53 −/− murine fibroblasts do not increase miR‐29 expression upon doxorubicin treatment. We have also found that miR‐29 represses Ppm1d phosphatase, which in turn enhances p53 activity. Based on these results, we propose the existence of a novel regulatory circuitry involving miR‐29, Ppm1d and p53, which is activated in aging and in response to DNA damage. Previous data from worms implicated miRNAs in lifespan regulation. Analysis of a mammalian progeria model now identifies a miRNA induced upon both premature and physiological aging, contributing to these processes via p53 and DNA damage response pathways.

Alterations in iron status have frequently been associated with obesity and other metabolic disorders. The hormone hepcidin stands out as a key regulator in the maintenance of iron homeostasis by controlling the main iron exporter, ferroportin. Here we demonstrate that the deficiency in the hepcidin repressor matriptase-2 (Tmprss6) protects from high-fat diet-induced obesity. Tmprss6 −/− mice show a significant decrease in body fat, improved glucose tolerance and insulin sensitivity, and are protected against hepatic steatosis. Moreover, these mice exhibit a significant increase in fat lipolysis, consistent with their dramatic reduction in adiposity. Rescue experiments that block hepcidin up-regulation and restore iron levels in Tmprss6 −/ − mice via anti-hemojuvelin (HJV) therapy, revert the obesity-resistant phenotype of Tmprss6 −/ − mice. Overall, this study describes a role for matritpase-2 and hepcidin in obesity and highlights the relevance of iron regulation in the control of adipose tissue function. Iron homeostasis dysfunctions have been associated with several metabolic disorders including obesity, steatosis and diabetes. Here the authors demonstrate that the hepcidin repressor matriptase-2 regulates adiposity and its deficiency protects mice against obesity and promotes lipolysis.

Sensors based on spin qubits in 2D crystals offer the prospect of nanoscale proximities between sensor and source, which could provide access to otherwise inaccessible signals. For AC magnetometry, the sensitivity and frequency range are typically limited by the noise spectrum, which determines the qubit coherence time. We address this using phase modulated continuous concatenated dynamic decoupling, which extends the coherence time towards the T 1 limit at room temperature and enables tuneable narrowband AC magnetometry. Using an ensemble of negatively charged boron vacancies in hexagonal boron nitride, we detect out-of-plane AC fields in the range of ~ 10 − 150 MHz, and in-plane fields within ± 150 MHz of the electron spin resonance. We measure an AC magnetic field sensitivity of ~ 1 μ T / Hz at ~ 2.5 GHz, for a sensor volume of ~ 0.1 μm 3 . This work establishes the viability of spin defects in 2D materials for high frequency magnetometry, with wide-ranging applications across science and technology.

Solid-state spin–photon interfaces that combine single-photon generation and long-lived spin coherence with scalable device integration—ideally under ambient conditions—hold great promise for the implementation of quantum networks and sensors. Despite rapid progress reported across several candidate systems, those possessing quantum coherent single spins at room temperature remain extremely rare. Here we report quantum coherent control under ambient conditions of a single-photon-emitting defect spin in a layered van der Waals material, namely, hexagonal boron nitride. We identify that the carbon-related defect has a spin-triplet electronic ground-state manifold. We demonstrate that the spin coherence is predominantly governed by coupling to only a few proximal nuclei and is prolonged by decoupling protocols. Our results serve to introduce a new platform to realize a room-temperature spin qubit coupled to a multiqubit quantum register or quantum sensor with nanoscale sample proximity. Quantum coherent control of single-photon-emitting defect spins have been reported in hexagonal boron nitride, revealing that spin coherence is mainly governed by coupling to a few proximal nuclei and can be prolonged by decoupling protocols.

The stability of spin of macroscopic quantum states to intrinsic noise is studied for non-resonantly-pumped optically-trapped polariton condensates. We demonstrate flipping between the two spin-polarised states with >104 slow-down of the flip rate by tuning the optical pump power. Individual spin flips faster than 50 ps are time resolved using single-shot streak camera imaging. We reproduce our results within a mean-field model accounting for cross-spin scattering between excitons and polaritons, yielding a ratio of cross- to co-spin scattering of ∼0.6, in contrast with previous literature suggestions.