Magnetic-Field Probing of an SU(4) Kondo Resonance in a Single-Atom Transistor

Semiconductor devices have been scaled to the point that transport can be dominated by only a single dopant atom. As a result, in a Si fin-type field effect transistor Kondo physics can govern transport when one electron is bound to the single dopant. Orbital (valley) degrees of freedom, apart from the standard spin, strongly modify the Kondo...

Lifetime-Enhanced Transport in Silicon due to Spin and Valley Blockade

We report the observation of lifetime-enhanced transport (LET) based on perpendicular valleys in silicon by transport spectroscopy measurements of a two-electron system in a silicon transistor. The LET is manifested as a peculiar current step in the stability diagram due to a forbidden transition between an excited state and any of the lower...

Electric field reduced charging energies and two-electron bound excited states of single donors in silicon

We present atomistic simulations of the D0 to D? charging energies of a gated donor in silicon as a function of applied fields and donor depths and find good agreement with experimental measurements. A self-consistent field large-scale tight-binding method is used to compute the D? binding energies with a domain of over 1.4 million atoms, taking...

Engineered valley-orbit splittings in quantum-confined nanostructures in silicon

An important challenge in silicon quantum electronics in the few electron regime is the potentially small energy gap between the ground and excited orbital states in 3D quantum confined nanostructures due to the multiple valley degeneracies of the conduction band present in silicon. Understanding the “valley-orbit” (VO) gap is essential for...

Heterointerface effects on the charging energy of the shallow D? ground state in silicon: Role of dielectric mismatch

Donor states in Si nanodevices can be strongly modified by nearby insulating barriers and metallic gates. Experimental results indicate a strong reduction in the charging energy of isolated As dopants in Si nonplanar field effect transistors relative to the bulk value. By studying the problem of two electrons bound to a shallow donor within the...

Coherent transport through a double donor system in silicon

In this letter, we describe the observation of the interference of conduction paths induced by two donors in a nanoscale silicon transistor, resulting in a Fano resonance. This demonstrates the coherent exchange of electrons between two donors. In addition, the phase difference between the two conduction paths can be tuned by means of a magnetic...

Ternary logic implemented on a single dopant atom field effect silicon transistor

We provide an experimental proof of principle for a ternary multiplier realized in terms of the charge state of a single dopant atom embedded in a fin field effect transistor (Fin-FET). Robust reading of the logic output is made possible by using two channels to measure the current flowing through the device and the transconductance. A read out...

Orbital Stark effect and quantum confinement transition of donors in silicon

Adiabatic shuttling of single impurity bound electrons to gate-induced surface states in semiconductors has attracted much attention in recent times, mostly in the context of solid-state quantum computer architecture. A recent transport spectroscopy experiment for the first time was able to probe the Stark shifted spectrum of a single donor in...

Subthreshold channels at the edges of nanoscale triple-gate silicon transistors

The authors investigate the subthreshold behavior of triple-gate silicon field-effect transistors by low-temperature transport experiments. These three-dimensional nanoscale devices consist of a lithographically defined silicon nanowire surrounded by a gate with an active region as small as a few tens of nanometers down to 50×60×35?nm3....

Transport Spectroscopy of a Single Dopant in a Gated Silicon Nanowire

We report on spectroscopy of a single dopant atom in silicon by resonant tunneling between source and drain of a gated nanowire etched from silicon on insulator. The electronic states of this dopant isolated in the channel appear as resonances in the low temperature conductance at energies below the conduction band edge. We observe the two...