Single-spin detection and read-out for the solid-state quantum computer via resonant techniques

Direct single-spin detection for read-out in solid-state quantum computing architectures is a difficult problem due to the isolation of the spin qubit from its environment. Converting the problem to one of charge measurement is advantageous as we can measure the charge qubit using a single electron transistor (SET). The read-out state for the standard Si:P architecture -- a doubly occupied donor state D- -- results from spin-dependent electron tunneling between donors. Complications arise due to the low binding energy of this state, meaning existing adiabatic transfer schemes may cause ionisation of the D- state before measurement can be performed by the SET. We describe a new method for the read-out of spin qubits, using gated electric fields at resonance with the transition being measured, to resonantly transfer a single electron to the SET using small DC fields. In addition to this we propose an extension to this method where a far-infrared laser (FIR) induces the resonant transfer.

[1]  David M. Larsen,et al.  Stress dependence of the binding energy ofD−centers in Si , 1981 .

[2]  G. Feher,et al.  Electron Spin Resonance Experiments on Donors in Silicon. I. Electronic Structure of Donors by the Electron Nuclear Double Resonance Technique , 1959 .

[3]  G. A. Thomas,et al.  Optical study of interacting donors in semiconductors , 1981 .

[4]  Marvin J. Weber,et al.  Handbook of Laser Wavelengths , 1998 .

[5]  Robert Joynt,et al.  Spin readout and initialization in a semiconductor quantum dot. , 2004, Physical review letters.

[6]  L. Vandersypen,et al.  Single-shot read-out of an individual electron spin in a quantum dot , 2004, Nature.

[7]  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 .

[8]  D. Gammon,et al.  Optical read-out and initialization of an electron spin in a single quantum dot , 2003 .

[9]  A. G. Fowler,et al.  Single-spin readout for buried dopant semiconductor qubits , 2004, quant-ph/0402077.

[10]  B. Chui,et al.  Single spin detection by magnetic resonance force microscopy , 2004, Nature.

[11]  D. Gammon,et al.  Optical read-out and initialization of an electron spin in a single quantum dot , 2003, Postconference Digest Quantum Electronics and Laser Science, 2003. QELS..

[12]  B. E. Kane.  A silicon-based nuclear spin quantum computer , 1998, Nature.

[13]  Andrew D. Greentree,et al.  Electrical readout of a spin qubit without double occupancy , 2005 .

[14]  S. Bandyopadhyay.  Single-spin measurement in the solid state: A reader for a spin qubit , 2003 .