Pulsed low-field electrically detected magnetic resonance

Abstract

We present pulsed electrically detected magnetic resonance (EDMR) measurements at low magnetic fields using phosphorus-doped silicon with natural isotope composition as a model system. Our measurements show that pulsed EDMR experiments, well established at X-band frequencies (10 GHz), such as coherent spin rotations, Hahn echoes, and measurements of parallel and antiparallel spin pair life times are also feasible at frequencies in the MHz regime. We find that the Rabi frequency of the coupled 31 P electron-nuclear spin system scales with the magnetic field as predicted by the spin Hamiltonian, while the measured spin coherence and recombination times do not strongly depend on the magnetic field in the region investigated. The usefulness of pulsed lowfield EDMR for measurements of small hyperfine interactions is demonstrated by electron spin echo envelope modulation measurements of the P b0 dangling-bond state at the Si/SiO2 interface. A pronounced modulation with a frequency at the free Larmor frequency of hydrogen nuclei was observed for radio frequencies between 38 MHz and 400 MHz, attributed to the nuclear magnetic resonance of hydrogen in an adsorbed layer of water. This demonstrates the high sensitivity of low-field EDMR also for spins not directly participating in the spin-dependent transport investigated.

Optical Dependence of Electrically Detected Magnetic Resonance in Lightly Doped Si:P Devices

“…On the other hand, the ability to lithographically pattern structures on silicon surfaces could enable the design of sensor arrays which are highly scalable. As Dreher et al have shown previously, EDMR can be used to detect protons adsorbed onto the silicon surface, analogous to NMR measured by way of NV centers [21]. This coupling between interfacial P b0 defects and surface nuclear spin species has also been observed in dynamic nuclear polarization experiments [45,46].…”

“…Table II shows the parameters in these simulations. Dreher et al have reported singlet and triplet recombination time constants to be 15 µs and 2 ms respectively in Si:P [21]. However the other rates for this system have not been measured to date.…”

“…EDMR in Si:P has been used to electrically detect donor spin states [18], and to readout an ensemble nuclear spin memory with extremely long lifetimes (> 100 s) [19]. Silicon EDMR has been integrated with photoconductive AFM into a scanning probe microscope [20] and has been used to detect the protons from water adsorbed onto the silicon surface [21].…”

Measuring spin relaxation with standard pulse sequences in the singlet–triplet basis

“…Phase cycling has been extensively studied in the context of Nuclear Magnetic Resonance [52,53] and ESR [54,55] experiments. Recently it was demonstrated for pEDMR [56] and since then it has been used in electrically-detected double electron-electron resonance, electron spin echo envelope modulation and inversion recovery [57,58,38,59,60], although its' general applicability has not been discussed.…”

“…As such, we can usually discuss the spin-dependent rates in terms of the product basis, consisting of parallel (j ""i; j ##i) and anti-parallel (j "#i; j #"i) pairs [32]. The introduction of exchange or dipolar coupling, real-time [37] readout, or low-field measurement [38] (when B 0 is comparable to the Overhauser field or zero-field splitting) will weaken the spin mixing between the singlet and T 0 states and modify the transient dynamics. These effects are beyond the scope of this paper.…”