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 effect in such systems. Owing to the small size and the s-like orbital symmetry of the ground state of the dopant, these orbital degrees of freedom do not couple to external magnetic fields which allows us to tune the symmetry of the Kondo effect. Here we study this tunable Kondo effect and demonstrate experimentally a symmetry crossover from an SU(4) ground state to a pure orbital SU(2) ground state as a function of magnetic field. Our claim is supported by theoretical calculations that unambiguously show that the SU(2) symmetric case corresponds to a pure valley Kondo effect of fully polarized electrons.

[1]  From the Kondo Regime to the Mixed-Valence Regime in a Single-Electron Transistor , 1998, cond-mat/9807233.

[2]  N. Collaert,et al.  Tunable Kondo effect in a single donor atom. , 2009, Nano letters.

[3]  Carl R. Pidgeon,et al.  Coherent control of Rydberg states in silicon , 2010, Nature.

[4]  X. Jehl,et al.  Single-dopant resonance in a single-electron transistor , 2010, 1012.5544.

[5]  Belita Koiller,et al.  Electric-field control and adiabatic evolution of shallow donor impurities in silicon , 2004 .

[6]  A. Aldea,et al.  Coulomb oscillations in the Fano-Kondo effect and zero-bias anomalies in a double-dot mesotransistor , 2011, 1101.5439.

[7]  R. Joynt,et al.  Valley Kondo effect in silicon quantum dots , 2006, cond-mat/0611722.

[8]  Kondo effects in carbon nanotubes: From SU(4) to SU(2) symmetry , 2006, cond-mat/0608110.

[9]  Hill,et al.  Fermi-edge singularity in resonant tunneling. , 1994, Physical review letters.

[10]  小谷 正雄.  日本物理学会誌及びJournal of the Physical Society of Japanの月刊について , 1955 .

[11]  J. Kong,et al.  Orbital Kondo effect in carbon nanotubes , 2005, Nature.

[12]  A. Hewson,et al.  The Kondo Problem to Heavy Fermions: Addendum , 1993 .

[13]  Insoo Woo,et al.  Gate-induced quantum-confinement transition of a single dopant atom in a silicon FinFET , 2008 .

[14]  J. Thomson,et al.  Philosophical Magazine , 1945, Nature.

[15]  N. Collaert,et al.  Lifetime-enhanced transport in silicon due to spin and valley blockade. , 2010, Physical review letters.

[16]  Leo P. Kadanoff,et al.  Quantum Statistical Mechanics , 2018 .

[17]  Y. Liu,et al.  Transport properties of a Kondo dot with a larger side-coupled noninteracting quantum dot , 2008 .

[18]  Orbital fluctuations and strong correlations in quantum dots , 2005, cond-mat/0505767.

[19]  X Jehl,et al.  Single-donor ionization energies in a nanoscale CMOS channel. , 2010, Nature nanotechnology.

[20]  Matthew J. Rosseinsky,et al.  Physical Review B , 2011 .

[21]  Enhancement of Kondo Effect in Multilevel Quantum Dots , 2004, cond-mat/0408159.

[22]  October I.  Physical Review Letters , 2022 .

[23]  A. Müller.  Journal of Physics Condensed Matter , 2008 .

[24]  Andrew G. Glen,et al.  APPL , 2001 .

[25]  W. Marsden.  I and J , 2012 .

[26]  G. Finkelstein,et al.  SU(2) and SU(4) Kondo effects in carbon nanotube quantum dots , 2007, 0709.1288.

[27]  J. Devreese,et al.  Linear and Nonlinear Electron Transport in Solids , 1976 .

[28]  R. Rosenfeld.  Nature , 2009, Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery.

[29]  G. Feher,et al.  Electron Spin Resonance Experiments on Donors in Silicon. III. Investigation of Excited States by the Application of Uniaxial Stress and Their Importance in Relaxation Processes , 1961 .

[30]  Xuedong Hu,et al.  Quantum control of donor electrons at the Si-SiO2 interface. , 2006, Physical review letters.

[31]  N. Collaert,et al.  Coherent transport through a double donor system in silicon , 2009, 0912.2196.

[32]  SU(4) Fermi liquid state and spin filtering in a double quantum dot system. , 2002, Physical review letters.

[33]  Kouwenhoven,et al.  A tunable kondo effect in quantum dots , 1998, Science.

[34]  M Jurczak,et al.  Transport spectroscopy of a single dopant in a gated silicon nanowire. , 2006, Physical review letters.