Einstein Hmmm

The rate at which quantum computing is hitting the media stream is ever-increasing. This piece is a collection of recent articles and reports covering various aspects of quantum computing from the lens of science and research. Mea Cubitt

Clifford Circuit Optimization with Templates and Symbolic Pauli Gates | The Clifford group is a finite subgroup of the unitary group generated by the Hadamard, the CNOT, and the Phase gates. This group plays a prominent role in quantum error correction, randomized benchmarking protocols, and the study of entanglement. Here we consider the problem of finding a short quantum circuit implementing a given Clifford group element. Our methods aim to minimize the entangling gate count assuming all-to-all qubit connectivity. First, we consider circuit optimization based on template matching and design Clifford-specific templates that leverage the ability to factor out Pauli and SWAP gates. Second, we introduce a symbolic peephole optimization method. It works by projecting the full circuit onto a small subset of qubits and optimally recompiling the projected subcircuit via dynamic programming. CNOT gates coupling the chosen subset of qubits with the remaining qubits are expressed using symbolic Pauli gates. Software implementation of these methods finds circuits that are only 0.2% away from optimal for 6 qubits and reduces the two-qubit gate count in circuits with up to 64 qubits by 64.7% on average, compared with the Aaronson-Gottesman canonical form.  Source: Quantum the open journal for quantum science.   Clifford Circuit Optimization with Templates and Symbolic Pauli Gates…

Randomized Benchmarking as Convolution: Fourier Analysis of Gate Dependent Errors | We show that the Randomized Benchmarking (RB) protocol is a convolution amenable to Fourier space analysis. By adopting the mathematical framework of Fourier transforms of matrix-valued functions on groups established in recent work from Gowers and Hatami [19], we provide an alternative proof of Wallman’s [32] and Proctor’s [28] bounds on the effect of gate-dependent noise on randomized benchmarking. We show explicitly that as long as our faulty gate-set is close to the targeted representation of the Clifford group, an RB sequence is described by the exponential decay of a process that has exactly two eigenvalues close to one and the rest close to zero. This framework also allows us to construct a gauge in which the average gate-set error is a depolarizing channel parameterized by the RB decay rates, as well as a gauge which maximizes the fidelity with respect to the ideal gate-set.  Source: Quantum the open journal for quantum science.   Randomized Benchmarking as Convolution: Fourier Analysis of Gate Dependent Errors…

Physicists reveal non-reciprocal flow around the quantum world | IQM’s Q-Exa Consortium Selected to Integrate German Quantum Computer Into HPC Supercomputer for the First Time  Source: PHYS.ORG (University of Exter).   Physicists reveal non-reciprocal flow around the quantum world…

New powerful method to explore phase transitions in strongly correlated quantum systems | Researchers from Aalto University and Tampere University have developed a new theoretical method to study dynamical phase transitions in strongly correlated quantum systems. Far-from-equilibrium dynamics of quantum many-body systems is one of the most active research areas in physics. The breakthrough work was recently published in Physical Review X.  Source: PHYS.ORG (Aalto University).   New powerful method to explore phase transitions in strongly correlated quantum systems…

Pauli blocking is spotted in ultracold fermionic gases | A manifestation of the Pauli exclusion principle in ultracold atomic gases has been spotted for the first time by three independent research groups. Called Pauli blocking, the effect was first predicted 30 years ago and occurs when fermionic atoms in a quantum gas are unable to make transitions to nearby quantum states.  Source: physicsworld.   Pauli blocking is spotted in ultracold fermionic gases…

User Submission: Quantum Computing: A road from illusion to promise | One of the most researched technologies of the current time, quantum computing, is poised to emerge as an enabling technology ushering in a golden era of computing, solving problems intractable on current day’s classical computers. In this Paper, tracing the developments of quantum computers, we discuss the current challenges in realization of practical systems and the promise they offer. Also discuss its potential applications, market prospects and a peep into the future.  Source: INDIAai.   User Submission: Quantum Computing: A road from illusion to promise…