skip to main content


Title: Experimental limits on the fidelity of adiabatic geometric phase gates in a single solid-state spin qubit

While it is often thought that the geometric phase is less sensitive to fluctuations in the control fields, a very general feature of adiabatic Hamiltonians is the unavoidable dynamic phase that accompanies the geometric phase. The effect of control field noise during adiabatic geometric quantum gate operations has not been probed experimentally, especially in the canonical spin qubit system that is of interest for quantum information. We present measurement of the Berry phase and carry out adiabatic geometric phase gate in a single solid-state spin qubit associated with the nitrogen-vacancy center in diamond. We manipulate the spin qubit geometrically by careful application of microwave radiation that creates an effective rotating magnetic field, and observe the resulting Berry phase signal via spin echo interferometry. Our results show that control field noise at frequencies higher than the spin echo clock frequency causes decay of the quantum phase, and degrades the fidelity of the geometric phase gate to the classical threshold after a few (~10) operations. This occurs in spite of the geometric nature of the state preparation, due to unavoidable dynamic contributions. In conclusion, we have carried out systematic analysis and numerical simulations to study the effects of the control field noisemore » and imperfect driving waveforms on the quantum phase gate.« less
 [1] ;  [1] ;  [1] ;  [1]
  1. Univ. of Pittsburgh, Pittsburgh, PA (United States). Dept. of Physics and Astronomy
Publication Date:
Grant/Contract Number:
SC0006638; SC 0006638
Published Article
Journal Name:
New Journal of Physics
Additional Journal Information:
Journal Volume: 18; Journal Issue: 5; Journal ID: ISSN 1367-2630
IOP Publishing
Research Org:
Univ. of Pittsburgh, Pittsburgh, PA (United States). Dept. of Physics and Astronomy
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; diamond; NV center; Berry phase; geometric phase; experimental realization; quantum computation
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1253426; OSTI ID: 1282051