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CN-122029633-A - Based on electron beam pumping-detection resonance spectroscopy

CN122029633ACN 122029633 ACN122029633 ACN 122029633ACN-122029633-A

Abstract

Method for time resolved pump-detection resonance spectroscopy comprising the steps of-exposing a sample (4) to a radio frequency pump pulse (20), wherein the radio frequency pump pulse (20) drives resonance, wherein the resonance is electron spin resonance and/or nuclear magnetic resonance, wherein the sample (4) is located within a magnetic bias field (22), -detecting the sample (4) with an electron detection beam (7) from an electron source (6), -detecting a detection beam characteristic of the electron detection beam (7) with a detector unit (8), wherein the detection beam characteristic depends on a magnetic moment (25) of the sample (4), wherein the magnetic moment (25) depends on the driven resonance, wherein the detector unit (8) is configured to detect the detection beam characteristic of the electron detection beam (7) with a time resolution for time resolved detection of the driven resonance, and determining a characteristic of the resonance, in particular a state of the resonance, preferably a change of the resonance state, based on the detected detection beam characteristic.

Inventors

  • P. Heislinger
  • D. Lazer
  • S. Nimrecht

Assignees

  • 维也纳工业大学

Dates

Publication Date
20260512
Application Date
20241010
Priority Date
20231010

Claims (9)

  1. 1. A method for time resolved pump-detection resonance spectroscopy, comprising the steps of: -exposing the sample (4) to a radio frequency pump pulse (20), wherein the radio frequency pump pulse (20) drives a resonance of the sample (4), wherein the resonance is electron spin resonance and/or nuclear magnetic resonance, wherein the sample (4) is located in a magnetic bias field (22); -detecting the sample (4) with an electron detection beam (7) from an electron source (6); -detecting a detection beam characteristic of the electron detection beam (7) with a detector unit (8), wherein the detection beam characteristic depends on a magnetic moment (25) of the sample (4), wherein the magnetic moment (25) depends on a driven resonance, wherein the detector unit (8) is configured to detect the detection beam characteristic of the electron detection beam (7) with a time resolution for time-resolved detection of the driven resonance, and -Determining a characteristic of the resonance, in particular a state of the resonance, preferably a change of the resonance state, based on the detected detection beam characteristic.
  2. 2. The method according to claim 1, wherein the probe beam characteristics comprise a deflection of the electron probe beam (7).
  3. 3. The method according to claim 1 or claim 2, wherein the probe beam characteristics comprise a phase shift of the electron probe beam (7).
  4. 4. A method according to claim 3, characterized by the further step of: -providing a reference electron beam (9) from the electron source (6); Wherein the reference electron beam (9) and the electron detection beam (7) interfere at least at the detector unit (8) and form an interference beam (10), wherein the detection of the phase shift is achieved by detecting the intensity of the interference beam (10).
  5. 5. The method according to claim 4, characterized in that the interference beam (10) comprises a holographic signal (21).
  6. 6. An electron microscope (1) for time-resolved pump-detection resonance spectroscopy, in particular a holographic transmission electron microscope or a stacked imaging transmission electron microscope, comprising: -a sample holder (3) for holding a sample (4); -a radio frequency pump pulse generator (5) for generating a radio frequency pump pulse (20) to drive resonance of the sample (4), wherein the resonance is electron spin resonance and/or nuclear magnetic resonance; -a magnetic bias field generator for generating a magnetic bias field (22) for biasing the sample (4); -an electron source (6) for irradiating the sample (4) with an electron probe beam (7); -a detector unit (8) for detecting a detection beam characteristic, in particular a phase shift and/or a deflection, of the electron detection beam (7), wherein the detection beam characteristic depends on a magnetic moment (25) of the sample (4), wherein the magnetic moment (25) depends on a driven resonance, wherein the detector unit (8) is configured to detect the detection beam characteristic with a time resolution for time-resolved detection of the driven resonance.
  7. 7. Electron microscope (1) according to claim 6, characterized in that the probe beam characteristics comprise a phase shift of the electron probe beam (7), wherein the electron source (6) is configured to provide an electron reference beam (9), the electron probe beam (7) and the electron reference beam (9) interfering and forming an interfering beam at least at the detector unit (8), wherein the detection of the phase shift is achieved by detecting the intensity of the interfering beam (10).
  8. 8. Electron microscope (1) according to claim 6 or 7, characterized in that an electron beam splitter, in particular an electron biprism (11), is arranged between the sample holder (3) and the detector unit (8) such that the electron probe beam (7) and the electron reference beam (9) interfere at the detector unit (8).
  9. 9. Electron microscope (1) according to one of claims 6 to 8, characterized in that the radiofrequency pump pulse generator (5) comprises an antenna, in particular a coil, wherein the antenna is adjacent to the sample (4).

Description

Based on electron beam pumping-detection resonance spectroscopy Technical Field The invention relates to a resonance spectrum (resonance spectroscopy) in combination with an electron microscope, in particular a spin resonance spectrum or a magnetic resonance spectrum. In particular, the invention relates to a method for time-resolved pump-probe resonance spectroscopy, and to an electron microscope, in particular a holographic transmission electron microscope or a stacked imaging transmission electron microscope (ptychography transmission electron microscope), for time-resolved pump-probe resonance spectroscopy. Background Electron microscopy, particularly Transmission Electron Microscopy (TEM), and its various advanced techniques, such as aberration correction or frozen sample preparation, are highly developed techniques that exploit the fluctuating nature of electrons to resolve atomic scale structures. Development of fast direct electron detectors (see X. Llopart, J. Alozy, R. Ballabriga, M. Campbell, R. Casanova, V. Gromov, E. Heijne, T. Poikela, E. Santin, V. Sriskaran, et al., Timepix4, a large area pixel detector readout chip providing sub-200 ps timestamp binning（ a large area pixel detector readout chip, which can provide sub-200 picosecond timestamp binning), journal of Instrumentation (01), C01044, (2022)) and ultrafast transmission electron microscopy techniques have initiated research into processes with both atomic scale spatial resolution and sub-picosecond temporal resolution (see, e.g., v.a. Lobastov, r.srinivasan, and a.h. Zewail, four-dimensional ultrafast electron microscopy ("four-dimensional ultrafast electron microscope"), proceedings of the National Academy of Sciences, 102, 7069 (2005), and a.h. Zewail, 4D ultrafast electron diffraction, crystallography, and microscales ("4D ultrafast electron diffraction") Crystallography and microscopy "), annual Review of PHYSICAL CHEMISTRY, 65 (2006)), even with specially optimized interferometry equipment (see, e.g., optimization of off-axis electroholography performed with femtosecond electronic pulses, F. Houdellier, G. M. Caruso, S. Weber, M. J. Hytch, C. Gatel, and A. Arbouet, Optimization of off-axis electron holography performed with femtosecond electron pulses（), ultramicroscopy, 26 (2019), and A. Arbouet, G. M. Caruso, and F. Houdellier, Ultrafast transmission electron microscopy: historical development, instrumentation, and applications （ ultra-fast transmission electron microscopy: historical development, Instruments and applications), ADVANCES IN IMAGING AND electronics 207, 1 (2018), and also ultra-fast transmission electron microscopy using laser-driven field emitters A. Feist, N. Bach, N. Rubiano da Silva, T. Danz, M. Möller, K. E. Priebe, T. Domröse, J. G. Gatzmann, S. Rost, J. Schauss, S. Strauch, R. Bormann, M. Sivis, S. Schäfer, and C. Ropers, Ultrafast transmission electron microscopy using a laser-driven field emitter: Femtosecond resolution with a high coherence electron beam（: femtosecond resolution of high coherence electron beams), ultramicroscopy, 176, 63 (2017). These ultra-fast pump-probe experiments are based on laser-triggered sample excitation (UV-IR) followed by high time resolution electronic detection. Resonance spectroscopy, particularly spin resonance spectroscopy or magnetic resonance spectroscopy, such as Nuclear Magnetic Resonance (NMR) and Electron Spin Resonance (ESR), is a non-invasive spectroscopy (imaging) technique that not only completely alters the fields of medical diagnostics, biology and chemistry, but also brings about revolutionary changes to high-precision measurements of basic physics. Furthermore, the technology is also used to characterize electrochemically stored electrode materials, which is critical to address the challenges of renewable energy conversion. The (spin or magnetic) resonance spectrum and the (transmission) electron microscope complement each other, which provide different insights into the structure, material and (chemical) process. Although magnetic resonance spectroscopy is generally non-invasive and has excellent spectral resolution, the spatial resolution of electron microscopy is higher. However, to date, no technology has provided the advantages and insights of both (transmission) electron microscopy and (spin or magnetic) resonance spectroscopy. JPH09281063a shows a magnetic resonance electron microscope suitable for observing the magnetization state of a magnetic material without being affected by a magnetic field even when the magnetic field is coexistent. CN 110231354A discloses a non-laser excited four-dimensional transmission electron microscope device. The built-in excitation device of the device applies a non-laser excitation method to the sample, including direct current pulse, radio frequency pulse, heat pulse or mechanical force pulse. The dynamic changes of the sample were recorded using a high speed camera. Disclosure of Invention It is therefore an