MINFLUX achieves molecular resolution with minimal photons
Related Articles
Diffraction minima resolve point scatterers at few hundredths of the wavelength
Resolving two or more constantly scattering identical point sources using freely propagating waves is limited by diffraction. Here we show that, by illuminating with a diffraction minimum, a given number of point scatterers can be resolved at distances of small fractions of the wavelength. Specifically, we identify an 8 nm distance, which corresponds to 1/80 of the employed 640 nm wavelength, between two constantly emitting fluorescent molecules in the focal plane of an optical microscope. We also measure 22 nm side length for a quadratic array of four molecules. Moreover, we show that the measurement precision improves with decreasing distance and with increased scatterer density. This work opens up the prospect of resolving individual scatterers in clusters that are far smaller than the wavelength.
Collective quantum enhancement in critical quantum sensing
Critical systems represent a valuable resource in quantum sensing and metrology. Critical quantum sensing (CQS) protocols can be realized using finite-component phase transitions, where criticality arises from the rescaling of system parameters rather than the thermodynamic limit. Here, we show that a collective quantum advantage can be achieved in a multipartite CQS protocol using a chain of parametrically coupled critical resonators in the weak-nonlinearity limit. We derive analytical solutions for the low-energy spectrum of this unconventional quantum many-body system, which is composed of locally critical elements. We then assess the scaling of the quantum Fisher information with respect to fundamental resources. We demonstrate that the coupled chain outperforms an equivalent ensemble of independent critical sensors, achieving quadratic scaling in the number of resonators. Finally, we show that even with finite Kerr nonlinearity or Markovian dissipation, the critical chain retains its advantage, making it relevant for implementing quantum sensors with current microwave superconducting technologies.
Full-field Brillouin microscopy based on an imaging Fourier-transform spectrometer
Brillouin microscopy is an emerging optical elastography technique that can be used to assess mechanical properties of biological samples in a three-dimensional, all-optical and hence non-contact fashion. However, the low cross-section of spontaneous Brillouin scattering produces weak signals that often necessitate prolonged exposure times or illumination dosages that are potentially harmful for biological samples. Here we present a new approach for highly multiplexed and therefore rapid spectral acquisition of the Brillouin-scattered light. Specifically, by exploiting a custom-built Fourier-transform imaging spectrometer and the symmetric properties of the Brillouin spectrum, we experimentally demonstrate full-field 2D spectral Brillouin imaging of phantoms as well as biological samples, at a throughput of up to 40,000 spectra per second, with a precision of ~70 MHz and an effective 2D image acquisition speed of 0.1 Hz over a ~300 × 300 µm2 field of view. This represents an approximately three-orders-of-magnitude improvement in speed and throughput compared with standard confocal methods, while retaining high spatial resolution and the capability to acquire three-dimensional images of photosensitive samples in biology and medicine.
Experimental benchmarking of quantum state overlap estimation strategies with photonic systems
Accurately estimating the overlap between quantum states is a fundamental task in quantum information processing. While various strategies using distinct quantum measurements have been proposed for overlap estimation, the lack of experimental benchmarks on estimation precision limits strategy selection in different situations. Here we compare the performance of four practical strategies for overlap estimation, including tomography-tomography, tomography-projection, Schur collective measurement and optical swap test using photonic quantum systems. We encode the quantum states on the polarization and path degrees of freedom of single photons. The corresponding measurements are performed by photon detection on certain modes following single-photon mode transformation or two-photon interference. We further propose an adaptive strategy with optimized precision in full-range overlap estimation. Our results shed new light on extracting the parameter of interest from quantum systems, prompting the design of efficient quantum protocols.
Full polarization control of photons with evanescent wave coupling in the ultra subwavelength gap of photonic molecules
Polarization of photons plays a key role in quantum optics and light-matter interactions, however, it is difficult to control in nanosystems since the eigenstate of a nanophotonic cavity is usually fixed and linearly polarized. Here, we reveal the polarization control of photons using photonic molecules (PMs) that host supermodes of two coupled nanobeam cavities. In contrast to conventional PMs in a 2D photonic crystal slab, for the two 1D photonic crystal nanobeam cavities the shift and gap between them can be tuned continuously. With an ultra subwavelength gap, the coupling between the two cavities is dominated by the evanescent wave coupling in the surrounding environment, rather not the emission wave coupling for conventional PMs. As such, the non-Hermiticity of the system becomes pronounced, and the supermodes consist of a non-trivial phase difference between bare eigenstates that supports elliptical polarization. We observe that both the polarization degree and polarization angle of the antisymmetric mode strongly depend on the shift and gap between the two cavities, exhibiting polarization states from linear to circular. This full polarization control indicates the great potential of PMs in quantum optical devices and spin-resolved cavity quantum electrodynamics.
Responses