2002/09/23 by M. I. Dykman, P. M. Platzman, P. Seddighrad · 6 citations
Physics and Astronomy · #Atomic physics #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Dephasing #Electron #Electron scattering #Excited state #Helium #Liquid helium #Physics #Quantum #Quantum and electron transport phenomena #Quantum decoherence #Quantum mechanics #Quantum, superfluid, helium dynamics #Qubit #Scattering #cond-mat.dis-nn #cond-mat.mes-hall #quant-ph
paper · pdf · doi:10.1103/physrevb.67.155402
15 pages, including 7 figures
arxiv created 2002/09/23 · openalex publication_date 2003/04/03 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study dissipation effects for electrons on the surface of liquid helium, which may serve as the qubits of a quantum computer. Each electron is localized in a 3D potential well formed by the image potential in helium and the potential from a submicron electrode submerged into helium. We estimate parameters of the confining potential and characterize the electron energy spectrum. Decay of the excited electron state is due to two-ripplon scattering and to scattering by phonons in helium. We identify mechanisms of coupling to phonons. An estimate of contributions from different scattering mechanisms shows that the decay rate should be \ensuremath\lesssim104s^\ensuremath-1. We analyze dephasing of the electron states due to quasielastic ripplon scattering off an electron. The dephasing rate is \ensuremath\lesssim102s^\ensuremath-1 for T=10mK and depends on temperature as T3. Decay and decoherence of the electron states result also from classical and quantum electrode noise. We relate the corresponding relaxation rates to the power spectrum of the fluctuating electric field on the electron. The dependence of the rates on the electrode parameters is obtained.