Kenneth R Brown CV

Journal article Physical review letters · December 2018 Featured Publication Coherent errors are a dominant noise process in many quantum computing architectures. Unlike stochastic errors, these errors can combine constructively and grow into highly detrimental overrotations. To combat this, we introduce a simple technique for supp ... Full text Open Access Cite

Spectroscopy of Molecular Ions in Coulomb Crystals.

Journal article The journal of physical chemistry letters · October 2018 Featured Publication In this Perspective, we examine the use of laser-cooled atomic ions and sympathetically cooled molecular ions in Coulomb crystals for molecular spectroscopy. Coulomb crystals are well-isolated environments that provide localization and long storage times f ... Full text Cite

Comparing Zeeman qubits to hyperfine qubits in the context of the surface code: 174Yb+ and 171Yb+

Journal article Phys. Rev. A · May 2, 2018 Featured Publication Many systems used for quantum computing possess additional states beyond those defining the qubit. Leakage out of the qubit subspace must be considered when designing quantum error correction codes. Here we consider trapped ion qubits manipulated by Raman ... Full text Link to item Cite

Simulating the performance of a distance-3 surface code in a linear ion trap

Journal article New Journal of Physics · April 1, 2018 Featured Publication We explore the feasibility of implementing a small surface code with 9 data qubits and 8 ancilla qubits, commonly referred to as surface-17, using a linear chain of 171Yb+ ions. Two-qubit gates can be performed between any two ions in ... Full text Cite

Rovibronic Spectroscopy of Sympathetically Cooled 40CaH+

Journal article The Journal of Physical Chemistry A · March 9, 2018 Featured Publication We measure the rovibronic transitions X 1Σ+, v″ = 0, J″ → A 1Σ+, v' = 0-3, J' of CaH+ and obtain rotational constants for the A 1Σ+ state. The spectrum is obtained using two-photon photodissociation of CaH+ cotrapped with Doppler cooled Ca+. The excitation ... Full text Cite

Robust 2-Qubit Gates in a Linear Ion Crystal Using a Frequency-Modulated Driving Force.

Journal article Physical review letters · January 2018 Featured Publication In an ion trap quantum computer, collective motional modes are used to entangle two or more qubits in order to execute multiqubit logical gates. Any residual entanglement between the internal and motional states of the ions results in loss of fidelity, esp ... Full text Open Access Cite

Reassigning the CaH⁺ 1¹Σ → 2¹Σ vibronic transition with CaD.

Journal article The Journal of chemical physics · December 2017 Featured Publication We observe vibronic transitions in CaD+ between the 11Σ and 21Σ electronic states by resonance enhanced multiphoton photodissociation spectroscopy in a Coulomb crystal. The vibronic transitions are compared with previous me ... Full text Cite

Fault-tolerant quantum error detection.

Journal article Science advances · October 2017 Featured Publication Quantum computers will eventually reach a size at which quantum error correction becomes imperative. Quantum information can be protected from qubit imperfections and flawed control operations by encoding a single logical qubit in multiple physical qubits. ... Full text Cite

Fault tolerance with bare ancillary qubits for a [[7,1,3]] code

Journal article Physical Review A · September 28, 2017 Featured Publication We present a [[7,1,3]] quantum error-correcting code that is able to achieve fault-tolerant syndrome measurement using one ancillary qubit per stabilizer for an error model of independent single-qubit Pauli errors. All single-qubit Pauli errors on the anci ... Full text Cite

Vibronic Spectroscopy of Sympathetically Cooled CaH.

Journal article Chemphyschem : a European journal of chemical physics and physical chemistry · November 2016 Featured Publication We report the measurement of the 11 Σ→21 Σ transition of CaH+ by resonance-enhanced photodissociation of CaH+ that is co-trapped with laser-cooled Ca+ . We observe four resonances that we assign to tra ... Full text Cite

Co-designing a scalable quantum computer with trapped atomic ions

Journal article Npj Quantum Information · January 1, 2016 Featured Publication The first generation of quantum computers are on the horizon, fabricated from quantum hardware platforms that may soon be able to tackle certain tasks that cannot be performed or modelled with conventional computers. These quantum devices will not likely b ... Full text Cite