For structural analysis of complex organic molecules and natural products, 2D homonuclear scalar-correlation NMR experiments are among the most useful tools for resolving ambiguities caused by overlapping signals in 1D spectra. Among the most widely used 1H-1H correlation experiments, COSY and TOCSY answer two different but complementary questions. COSY is mainly used to trace local proton-to-proton connectivity through observable J couplings, while TOCSY extends magnetization transfer through a continuous coupling network and helps identify all observable members of the same spin system. In practical terms, COSY helps answer "Which protons are coupled to each other?", while TOCSY helps answer "Which protons belong to the same spin system?" This article walks through the two experiments from pulse-sequence principles to practical spectrum interpretation, explaining their key differences and how they can be used together in 2D NMR spectroscopy. 1. Core Functions of COSY and TOCSY COSY, or Correlation Spectroscopy, and TOCSY, or Total Correlation Spectroscopy, both use scalar coupling, or J coupling, to provide proton correlation information through chemical bonds. However, the type of structural information they are designed to reveal is different. Consider a continuously coupled proton chain: H1 → H2 → H3 → H4 COSY: Local Coupling Connectivity COSY primarily detects directly observable scalar couplings between pairs of protons. The most common correlations arise from 2JHH and 3JHH couplings, for example: H1 ↔ H2H2 ↔ H3H3 ↔ H4 These pairwise correlations allow researchers to build the local proton connectivity step by step. In other words, a COSY spectrum is particularly useful when the goal is to reconstruct the sequential relationship between neighboring or otherwise detectably coupled protons. Note: COSY correlations are not restricted to two-bond and three-bond couplings. In allylic systems, aromatic systems, or rigid W-type geometries, a sufficiently strong 4J coupling, typically greater than about 1.5 Hz, may also generate a COSY cross peak. Therefore, the presence of a cross peak alone should not be taken as proof that two nuclei are directly adjacent in the molecular structure. TOCSY: Assignment of an Entire Spin System TOCSY takes a different approach. Through magnetization transfer across a J-coupled network, protons within the same continuous spin system can become correlated even when two particular protons do not show a strong direct coupling to each other. Its main purpose is therefore not to determine the direct connectivity of every proton pair. Instead, TOCSY is used to identify and group multiple protons that belong to the same spin system. For example, if H1, H2, H3, and H4 form a continuous coupling network, magnetization can propagate through the sequence: H1 → H2 → H3 → H4 As a result, correlations between more distant members of the system may appear in the TOCSY spectrum. Note: A...

In short Three research teams used CIQTEK ODMR instruments, including the scanning NV probe microscope (SNVM) and the diamond single-spin spectrometer, to move three different areas of advanced materials research forward.   A team at the Institute of Physics, Chinese Academy of Sciences, imaged spin waves in real space near magnetic defects and antiferromagnetically coupled stripe domains in YIG and LSMO films. They captured wavelength-selective scattering and, for the first time, a zig-zag wavefront distortion as spin waves crossed stripe domains.   A team at the University of Science and Technology of China stripped selenium out of 2D CuCrSe₂ by vacuum annealing. The resulting Se vacancies produced room-temperature ferromagnetism while the layered crystal structure stayed intact.   A team at the Institute of Semiconductors, Chinese Academy of Sciences, mapped how a transverse magnetic field mixes NV center spin states, weakens optical readout, and shifts the balance between the NV⁻ and NV⁰ charge states, all of which matter for keeping NV-based sensors stable in real-world magnetic environments.   Why this matters Optically detected magnetic resonance (ODMR) sits at the center of solid-state spin science. It is how researchers image microscopic magnetic fields, how they unpack spin dynamics, and how they turn a single atomic-scale defect in diamond into a working sensor. The three studies below all leaned on CIQTEK's ODMR product line, which includes the scanning NV probe microscope (SNVM) and the diamond single-spin spectrometer, to push into territory that older tools could not reach: spin wave imaging, room-temperature ferromagnetism in 2D materials, and the spin mixing behavior of NV centers themselves.   Here is what each team found, and why it matters for anyone building magnonic devices, spintronic materials, or diamond-based sensors. Study 1: Scanning NV imaging reveals how spin waves actually propagate Where it was published: SCIENCE CHINA Physics, Mechanics & Astronomy   Paper title: Visualizing modified spin-wave wavefronts near magnetic defects and domains using nitrogen-vacancy centers   Research group: The Li Yangmu group at the Institute of Physics, Chinese Academy of Sciences   The team used scanning NV imaging to perform real-space imaging and phase analysis of spin wave propagation and wavefronts near nanoscale magnetic defects and antiferromagnetically coupled stripe domains in magnetic thin films (YIG and LSMO). The work revealed wavelength-selective scattering and waveform modulation, giving device designers a new set of tools for building and tuning spin wave devices.   First, some background: why spin waves are hard to see Spin waves, also called magnons, are collective excitations of a magnetically ordered system. They carry information without the Joule heating losses that come with conventional charge-based devices, which makes them an attractive carrier for low-power, w...

CIQTEK Lists on the Shanghai STAR Market CIQTEK held its listing ceremony at the Shanghai Stock Exchange on August 11, 2026. The listing marks a new stage for the company as it continues to develop high-end scientific instruments. The company trades under stock code 688828 and develops, manufactures, and sells products including electron microscopes, electron paramagnetic resonance spectrometers, and nuclear magnetic resonance spectrometers.   Listing Information CIQTEK issued 40.0100 million shares at RMB 21.22 per share. The gross proceeds from the new share offering were RMB 849.0122 million. Following the offering, the company had 400.0100 million shares outstanding. In 2025, CIQTEK reported revenue of RMB 666.191845 million. The company is based in Hefei, Anhui Province.   From Research to Real-World Use CIQTEK focuses on turning research capabilities into instruments that can be used in laboratories and industrial settings. At the ceremony, Dr. He Yu, Chairman of CIQTEK, said the listing is an important milestone and a stage in the company’s journey from the laboratory to real-world use. Dr. He thanked customers, partners, investors, and the teams that supported the offering and listing process.   A Focus on Useful, Reliable Instruments CIQTEK develops high-end scientific instruments across several product areas. The company continues to invest in research and development and to expand its product portfolio around customer needs. Dr. He said that customer feedback, technical problem-solving, and reliable delivery are central to the company’s long-term improvement. CIQTEK will continue to advance projects funded by the offering and strengthen transparent, standardized governance.   Looking Ahead Dr. He noted that better measurement tools support scientific discovery and that high-quality data remains essential as artificial intelligence changes the way research is done. CIQTEK will continue to build instruments for researchers and industrial users around the world. “We will stay focused, keep improving over the long term, and move forward steadily,” Dr. He said in closing.   Reprint Note The opening and “Listing Information” sections are reprinted from a Shanghai Stock Exchange public release. The remaining sections are adapted from an original address by Dr. He Yu, Chairman of CIQTEK, delivered at the listing ceremony.