ARPES vacuum ultraviolet light source and closed-cycle cryogenic sample holder delivered to Cornell University

In March 2019, the vacuum ultraviolet light source and closed-cycle cryogenic sample holder designed and manufactured by FERMI INSTRUMENTS (Shanghai) Co., Ltd. completed installation and acceptance at Cornell University (www.cornell.edu). As the core component of the angle-resolved photoelectron spectroscopy system, all indicators met the design requirements and were officially delivered to the Laboratory of Atomic and Solid State Physics (LASSP) of Cornell University for use.

ARPES | BL series UV light source and multi-DOF sample holder

ARPES uses high-energy photons to irradiate solids to excite electrons, and obtains the fine electronic structure of solids by measuring electron energy and angular dispersion, with extremely high sensitivity. The ARPES machine indicators mainly rely on three key components:

Analyzer: The current mainstream is the DA30 hemispherical analyzer provided by SCIENTAOmicron.

Sample movement freedom and temperature control: The temperature of the sample will directly affect the thermal motion of electrons, thereby affecting the energy-momentum resolution of electron detection. In addition, in order to study the electronic structure evolution of complex quantum material phase transitions, the sample temperature is required to be as low as possible; on the other hand, in order to detect a sufficiently large momentum space, the sample is required to be able to move with multiple degrees of freedom. FERMI INSTRUMENTS is also accelerating the progress of research and development and industrialization, and it is expected that an ultra-low temperature multi-degree-of-freedom sample stage with an extreme temperature below 2K will be released this year.

There are four main requirements for high-resolution vacuum ultraviolet light sources:

High energy resolution, because the resolution of the light source directly affects the overall resolution of the system;

High throughput, the brightness of the light source determines the test efficiency and the resolution of the electron microscopic structure. The current brightness of the synchrotron radiation level is 1012 photons;

Multi-spectrum: Because different band structures respond inconsistently to different photon energies, for three-dimensional materials, different photon energies see different Kz, so variable photon energy is required to achieve full-range scanning.

Long life: As a core high-value component, users need ultraviolet light sources to work stably for a long time.

The two components delivered to Cornell University this time are both mature products of FERMI INSTRUMENTS.

Core Components | 5.5-axis closed-cycle cryogenic sample holder (SLTCCM5FD)

The 5.5-axis closed-cycle cryogenic sample holder (SLTCCM5FD) ensures multi-degree-of-freedom movement of the sample stage and has high-precision adjustment function, ensuring the position accuracy during sample testing. At the same time, it gets rid of the dependence on liquid helium and ensures accurate temperature control. The working range covers 5K~1321K during on-site acceptance.

The high brightness vacuum ultraviolet light source (BL-1000s) can efficiently excite a variety of gas components (He, Ne, Ar, Kr, Xe…), with a maximum luminous flux of >1017 Photons/Sr·sec, a lifespan of more than 10,000 hours, and can be used with gratings or filters to achieve a spectral output of less than 1meV. It is currently a strong vacuum ultraviolet light source at the laboratory level.