The interplay between disorder, quantum fluctuations, and dissipation is studied in the random transverse Ising chain coupled to a dissipative Ohmic bath with a real space renormalization group. A typically very large length scale $L^{*}$ is identified above which the physics of frozen clusters dominates. Below $L^{*}$ a strong-disorder fixed point determines scaling at a pseudocritical point. In a Griffiths-McCoy region frozen clusters produce already a finite magnetization resulting in a classical low temperature behavior of the susceptibility and specific heat. These override the confluent singularities that are characterized by a continuously varying exponent $z$ and are visible above a temperature $T^{*}\sim L^{*-z}$.

• Received 24 November 2005

DOI:https://doi.org/10.1103/PhysRevLett.96.227201