A table-top, repetitive pulsed magnet for nonlinear and ultrafast spectroscopy in high magnetic fields up to 30 T

Abstract

We have developed a mini-coil pulsed magnet system with direct optical access, ideally suited for nonlinear and ultrafast spectroscopy studies of materials in high magnetic fields up to 30 T. The apparatus consists of a small coil in a liquid nitrogen cryostat coupled with a helium flow cryostat to provide sample temperatures down to below 10 K. Direct optical access to the sample is achieved with the use of easily interchangeable windows separated by a short distance of ∼135 mm on either side of the coupled cryostats with numerical apertures of 0.20 and 0.03 for measurements employing the Faraday geometry. As a demonstration, we performed time-resolved and time-integrated photoluminescence measurements as well as transmission measurements on InGaAs quantum wells.

Dicke superradiance in solids [Invited]

“…In order to provide information on the widths of SF bursts quantitatively, TRPL measurements via a Kerr-gate technique were performed with a 30-T pulsed magnet in free space. Figure 17 shows a SF burst for the (11) transition at 10 T and 19 K [142]. By taking vertical and horizontal slices at the peak of the burst, the pulse width was estimated to be ∼ 10 ps, and the spectral width to be ∼ 5 meV.…”

“…We performed time-integrated photoluminescence (TIPL) spectroscopy, time-resolved photoluminescence (TRPL) spectroscopy, and time-resolved pump-probe spectroscopy measurements on the InGaAs QW sample under a variety of B, T , and P conditions, at the Ultrafast Optics Facility of the National High Magnetic Field Laboratory in Tallahassee, Florida (using either a 31-T DC resistive magnet or a 17.5-T superconducting magnet), and at Rice University with a 30-T pulsed magnet system [142]. The main laser system used was an amplified Ti:sapphire laser (Clark-MXR, Inc., CPA 2001, or Coherent Inc., Legend), producing 150 fs pulses of 775 nm (1.6 eV, with CPA 2001) or 800 nm (1.55 eV, with Legend) radiation at a repetition rate of 1 kHz.…”

Terahertz cyclotron resonance spectroscopy of an AlGaN/GaN heterostructure using a high-field pulsed magnet and an asynchronous optical sampling technique

“…The pulsed magnet used was similar to that described elsewhere, 9 but with an 8 mF capacitor bank that enabled the production of magnetic fields of up to 31 T. A sample temperature of 77 K was achieved inside the magnet bore by attaching the samples to the end of a sapphire tube (inner diameter 6 mm) that was connected to the cold finger of a continuous-flow cryostat (Microstat, Oxford Instruments). The ASOPS technique has previously been shown to enable nanosecond time delays to be achieved at kilohertz scan rates without the use of a mechanical delay stage.…”

“…7,8 Recently, compact pulsed magnets have been developed, which can provide the high magnetic fields (up to 30 T) that were previously only accessible at national-scale facilities on a table-top in a laboratory environment. 9 There have also been several reports of cyclotron resonance spectrometers being developed that combine pulsed magnetic fields with broadband laser-based terahertz radiation sources. [10][11][12] Laser-based terahertz spectroscopy is a timedomain technique that typically employs slow scanning mechanical delay stages to acquire the terahertz waveforms through combining time-delayed near-infrared and terahertz pulses in a nonlinear medium or photoconductive antenna.…”

Angular-Dependent EDMR Linewidth for Spin-Dependent Space-Charge-Limited Conduction in a Polycrystalline Pentacene

“…Various methods are available for multiple-frequency electron spin resonance (mf-ESR), using, for instance, a series of ESR instruments with a fixed microwave frequency (Krinichnvi et al, 2004) or stripline-type rather than resonator-type instruments at high frequency (>100 GHz) (Noe et al, 2013). Additionally, solenoid coils instead of a microwave cavity have been used in an mf-ESR apparatus at low frequencies of 1-60 MHz (Mizoguchi, 1995).…”