[摘要]：We develop a concept of atomic clocks where the blackbody radiation shift and its fluctuations can be suppressed by 1-3 orders of magnitude independent of the environmental temperature. The suppression is based on the fact that in a system with two accessible clock transitions (with frequencies nu(1) and nu(2)) which are exposed to the same thermal environment, there exists a "synthetic" frequency nu(syn) alpha (nu(1) - epsilon(12)nu(2)) largely immune to the blackbody radiation shift. For example, in the case of (171)Yb(+) it is possible to create a synthetic-frequency-based clock in which the fractional blackbody radiation shift can be suppressed to the level of 10(-18) in a broad interval near room temperature (300 +/- 15 K). We also propose a realization of our method with the use of an optical frequency comb generator stabilized to both frequencies nu(1) and nu(2), where the frequency nu(syn) is generated as one of the components of the comb spectrum.
