Coherence-Preserving Quantum Bits

Abstract

Real quantum systems couple to their environment and lose their intrinsic quantum nature through the process known as decoherence. Here we present a method for minimizing decoherence by making it energetically unfavorable. We present a Hamiltonian made up solely of two-body interactions between four two-level systems (qubits) which has a two-fold degenerate ground state. This degenerate ground state has the property that any decoherence process acting on an individual physical qubit must supply energy from the bath to the system. Quantum information can be encoded into the degeneracy of the ground state and such coherence-preserving qubits will then be robust to local decoherence at low bath temperatures. We show how this quantum information can be universally manipulated and indicate how this approach may be applied to a quantum dot quantum computer.

5 pages, 1 figure

Cited by in corpus (48)

• Operator Quantum Error Correcting Subsystems for Self-Correcting Quantum Memories
• Decoherence-Free Subspaces and Subsystems
• Quantum computing with spin cluster qubits
• Quantum computing with antiferromagnetic spin clusters
• Error correcting codes for adiabatic quantum computation
• Towards Fault Tolerant Adiabatic Quantum Computation
• Prospects for Quantum Enhancement with Diabatic Quantum Annealing
• Combined encoding and decoupling solution to problems of decoherence and design in solid-state quantum computing
• Quantum speed limits for leakage and decoherence
• Collective processes of an ensemble of spin-1/2 particles
• Quantum Chaos, Delocalization, and Entanglement in Disordered Heisenberg Models
• Quantum Dot Cluster State Computing with Encoded Qubits
• Coherence stabilization of a two-qubit gate by AC fields
• Collective Uncertainty in Partially-Polarized and Partially-Decohered Spin-1/2 Systems
• Exchange Interaction Between Three and Four Coupled Quantum Dots: Theory and Applications to Quantum Computing
• Multi-qubit compensation sequences
• Quantum Computation Beyond the Circuit Model
• Decoherence Free Subspace and entanglement by interaction with a common squeezed bath
• Optimized design of universal two-qubit gates
• Robust two-qubit quantum registers
• Energetic Suppression of Decoherence in Exchange-Only Quantum Computation
• Preparation of Decoherence Free Cluster States with Optical Superlattices
• The Quantum Governor: Automatic quantum control and reduction of the influence of noise without measuring
• Quantum parameter estimation with imperfect reference frames
• Adiabatic topological quantum computing
• A Scalable Architecture for Coherence-Preserving Qubits
• The Stability of Quantum Concatenated Code Hamiltonians
• Energy protection arguments fail in the interaction picture
• Few-body spin couplings and their implications for universal quantum computation
• Rotationally-Invariant Circuits: Universality with the exchange interaction and two ancilla qubits
• A Study on the Noise Threshold of Fault-tolerant Quantum Error Correction
• Theory of Quantum Circuits with Abelian Symmetries
• Faster quantum computation with permutations and resonant couplings
• Two-qubit gates for decoherence-free qubits using a ring exchange interaction
• Entanglement Sudden Death in a Quantum Memory
• Relaxation and decoherence of qubits encoded in collective states of engineered magnetic structures
• Tailoring Effective Exchange Interactions via Domain Walls in Coupled Heisenberg Rings
• Improving the purity of one- and two-qubit gates by AC fields
• Automated searching for quantum subsystem codes
• A Chain-Boson Model for the Decoherence and Relaxation of a Few Coupled SQUIDs in a Phonon Bath
• Monte Carlo analysis of critical phenomenon of the Ising model on memory stabilizer structures
• Using copies to improve precision in continuous-time quantum computing
• Parameter Estimation, Model Reduction and Quantum Filtering
• Robust preparation and manipulation of protected qubits using time--varying Hamiltonians
• Singlet-only Always-on Gapless Exchange Qubits with Baseband Control
• The Spin Density Matrix I: General Theory and Exact Master Equations
• The qubit states decoherence in antiferromagnet-based nuclear spin model of quantum register
• Quantum Gates Between Two Spins in a Triple Dot System with an Empty Dot