Low-temperature scanning tunneling microscope using closed-cycle refrigerator to achieve refrigeration

Abstract

The invention discloses a low-temperature scanning tunneling microscope using a closed-cycle refrigerator to achieve refrigeration. The low-temperature scanning tunneling microscope comprises a closed-cycle refrigerator system, a helium heat exchange gas refrigeration vibration isolation interface system, a low-temperature scanning tunneling microscope scanning head system, a vacuum system, a vibration reduction platform and a scanning tunnel microscope control system. According to the low-temperature scanning tunneling microscope, under the condition that no liquid helium is consumed, atomic-scale resolution low-temperature ultrahigh-vacuum scanning tunnel microscopy space imaging and high-energy resolution scanning tunnel spectrum accurate measurement can be achieved like a liquid helium refrigeration system. The technical scheme of closed-cycle refrigeration can also be used for other applications needing lower temperature and low-vibration environments like other members of scanning probe microscope families. Large-range temperature changes can also be achieved through feedback combination of heating elements and temperature measuring elements.

Description

technical field [0001] The invention belongs to the field of scanning probe microscopes, and in particular relates to a low-temperature scanning tunneling microscope which utilizes a closed-cycle refrigerator to refrigerate without consuming liquid helium. technical background [0002] Scanning Tunneling Microscope (STM) is a major member of the Scanning Probe Microscope (SPM) family, invented in 1982 by Binnig and Rohrer of IBM in Zurich, Switzerland. It works using the electron tunneling effect in quantum mechanics. Specifically, when an atomically sharp metal tip is infinitely close to the surface of the probed sample, until only a few or one atom away, if a bias voltage is applied between the probed sample and the metal tip, the tip or the sample will The electrons will tunnel through the vacuum barrier between the two, thus forming a tunneling current. Since the size of the tunneling current decays exponentially with the distance between the tip and the sample, the sc...

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Problems solved by technology

[0005] In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a low-temperature scanning tunneling microscope that utilizes a closed-cycle refrigerator for refrigeration, which does not need to consume liquid helium for refrigeration, has atomic-level resolution, and solves the problem of closed-cycle refrigerators. The problem of mechanical vibration around or above the micron level, so as to realize low-temperature space imaging and high-energy resolution scanning tunneling spectrum precision measurement

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