Polarization of a Charge Qubit Strongly Coupled to a Voltage-Driven Quantum Point Contact

2006/12/31 by Izak Snyman, I. Snyman, Y. V. Nazarov +1 · 21 citations
Chemistry · Computer Science · Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #Atomic physics #Charge qubit #Chemistry #Condensed matter physics #Coupling (piping) #Materials science #Phase qubit #Physics #Polarization (electrochemistry) #Quantum #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum mechanics #Quantum point contact #Quantum well #Qubit #cond-mat.mes-hall

paper · pdf · doi:10.1103/physrevlett.99.096802

published in Physical Review Letters 99(9), 096802 (American Physical Society) · 7 pages, 6 figures

arxiv created 2006/12/31 · openalex publication_date 2007/08/31 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We study a charge qubit with level splitting \ensuremathε, coupled to a quantum point contact driven by voltage V. In the limit of weak coupling, the qubit polarization shows cusps at \ensuremathε=\ifmmode±\else\textpm\fieV. We show that, for stronger couplings, prominent peculiarities occur at fractions \ensuremathε=\ifmmode±\else\textpm\fieV/2. Further increase of the coupling leads to a polarization corresponding to a pseudo Boltzmann distribution with an effective temperature \ensuremath∼eV.

Citations

• Electron counting statistics and coherent states of electric current
• Proposal for Production and Detection of Entangled Electron-Hole Pairs in a Degenerate Electron Gas
• Fermi-Edge Resonance and Tunneling in Nonequilibrium Electron Gas
• Dephasing and the Orthogonality Catastrophe in Tunneling through a Quantum Dot: the ``Which Path?'' Interferometer
• Few-electron quantum dot circuit with integrated charge read out
• Dephasing in a quantum dot due to coupling with a quantum point contact
• Full counting statistics of a general quantum mechanical variable
• Quantum Tunneling Detection of Two-Photon and Two-Electron Processes

Cited by

• Charge Fractionalization in the Two-Channel Kondo Effect
• Inelastic Backaction due to Quantum Point Contact Charge Fluctuations
• Electron-electron correlations in a dynamical impurity system with a Fermi edge singularity