Strong Algorithmic Cooling in Large Star-Topology Quantum Registers

Abstract

Cooling the qubit into a pure initial state is crucial for realizing fault-tolerant quantum information processing. Here we envisage a star-topology arrangement of reset and computation qubits for this purpose. The reset qubits cool or purify the computation qubit by transferring its entropy to a heat-bath with the help of a heat-bath algorithmic cooling procedure. By combining standard NMR methods with powerful quantum control techniques, we cool central qubits of two large star topology systems, with 13 and 37 spins respectively. We obtain polarization enhancements by a factor of over 24, and an associated reduction in the spin temperature from 298 K down to 12 K. Exploiting the enhanced polarization of computation qubit, we prepare combination-coherences of orders up to 15. By benchmarking the decay of these coherences we investigate the underlying noise process. Further, we also cool a pair of computation qubits and subsequently prepare them in an effective pure-state.

9 pages, 10 figures; close to published version

References in corpus (7)

• Magnetic field sensing beyond the standard quantum limit using 10-spin NOON states
• Benchmarking quantum control methods on a 12-qubit system
• A spin based heat engine: demonstration of multiple rounds of algorithmic cooling
• The Asymptotic Cooling of Heat-Bath Algorithmic Cooling
• Implementation of NMR quantum computation with para-hydrogen derived high purity quantum states
• Hyperfine spin qubits in irradiated malonic acid: heat-bath algorithmic cooling
• Spectral investigation of the noise influencing multi-qubit states

Cited by in corpus (11)

• Temporal order in periodically driven spins in star-shaped clusters
• NMR investigations of quantum battery using star-topology spin systems
• Observation of quantum phase-synchronization in a nuclear spin-system
• Novel Technique for Robust Optimal Algorithmic Cooling
• Ancilla Induced Amplification of Quantum Fisher Information
• Controlling NMR spin systems for quantum computation
• Bang-Bang Optimal Control of Large Spin Systems: Enhancement of ${}^{13}$C-${}^{13}$C Singlet-Order at Natural Abundance
• State-independent robust heat-bath algorithmic cooling of nuclear spins
• Experimental Implementation of a NMR NOON State Thermomete
• Asymptotic freedom in the dephased charging of quantum batteries
• Star-topology Registers: NMR and Quantum Information Perspectives