@article{18881, author = {Michael Mullan and Emanuel Knill}, title = {Improving Quantum Clocks via Semidefinite Programming}, year = {2012}, number = {12}, month = {2012-07-26}, publisher = {Quantum Information and Computation Journal}, url = {https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=909047}, language = {en}, }