Broadband electron spin resonance at 4–40 GHz and magnetic fields up to 10 T

Abstract

A broadband electron spin resonance spectrometer is described which operates at frequencies between 4 and 40 GHz and can be used in superconducting magnets. A tunable cylindrical cavity is connected to a vector network analyzer via coaxial cables, and the radiation is fed into the cavity by a coupling loop. No field modulation is employed. Resonance frequencies below 14 GHz are obtained by inserting dielectrics with different permittivities into the cavity. The setup allows for measurements with the microwave magnetic field either parallel or perpendicular to the external field.

Broadband Transmission EPR Spectroscopy

“…A high-frequency broadband version (40-60 GHz) has been described for flat solid samples [30]. A broadband form has been recently described for tuning over a 14-40 GHz frequency range extendable down to 4 GHz by insertion of sets of dielectric plates [31]. The setup has been tested with pure Mn 20 and V 6 molecular magnets but sensitivity has not yet been documented for doped solids or for dilute liquid samples.…”

Gd-Based Single-Ion Magnets with Tunable Magnetic Anisotropy: Molecular Design of Spin Qubits

“…Heat capacity measurements from T ¼ 350 mK up to room temperature were performed on a commercial physical measurement platform. Broadband electron paramagnetic resonance (EPR) spectroscopy was performed at T ¼ 1:7 K and T ¼ 10 K using a frequency tunable cavity [23]. Finally, pulsed EPR experiments on pure and magnetically diluted powder samples were performed using an Elexys X-band spectrometer.…”

Broadband electron spin resonance from 500 MHz to 40 GHz using superconducting coplanar waveguides

“…In this way small sample quantities can be probed over a wider frequency range. Setups that offer the possibility to sweep both the magnetic field and the radiation frequency have so far mostly been realized in the high frequency region (quasi-optical, from 50 to several 100 GHz) [6][7][8], while lower frequencies have been inspected using a coupled antenna approach [9], tuneable cavities [10] or by placing the sample close to the center conductor of a coaxial line [11].…”

“…In this way small sample quantities can be probed over a wider frequency range. Setups that offer the possibility to sweep both the magnetic field and the radiation frequency have so far mostly been realized in the high frequency region (quasi-optical, from 50 to several 100 GHz) [6][7][8], while lower frequencies have been inspected using a coupled antenna approach [9], tuneable cavities [10] or by placing the sample close to the center conductor of a coaxial line [11].In this letter we demonstrate a different approach which uses a microfabricated superconducting coplanar waveguide to generate the radio frequency (RF) field. The feasibility of such an approach was shown before by Schuster et al focusing on high-cooperativity coupling of spin ensembles to superconducting cavities [12].…”