EurekAlert February 11, 2021 Existing demonstrations of quantum correction codes (QEC) are hardware intensive and prone to introducing and propagating errors. A team of researchers in the US (UMass Amherst, Northwestern University) encoded a logical qubit in Schrödinger cat-like multiphoton states of a superconducting cavity and demonstrated a corrective dissipation process that stabilizes an error-syndrome operator, the photon number parity. Implemented with continuous-wave control fields only, this passive protocol protects the quantum information by autonomously correcting single-photon-loss errors and boosts the coherence time of the bosonic qubit by over a factor of two. QEC is realized in a modest hardware […]
Tag Archives: Quantum computing
Tiny bubbles make a quantum leap
EurekAlert July 13, 2020 An international team of researchers (USA – UC Berkeley, Columbia University, industry, Montana State University, Germany, Japan) found that placing sufficient strain in a 2D material–tungsten diselenide creates localized states that can yield single-photon emitters. The team was able to directly image these states for the first time, revealing that even at room temperature they are highly tunable and act as quantum dots, tightly confined pieces of semiconductors that emit light. Fully tunable, room-temperature single-photon emitters are now within our grasp, paving the way for controllable–and practical quantum photonic devices. These devices can be the foundation […]
NIST scientists create new recipe for single-atom transistors
EurekAlert May 11, 2020 Using a room temperature grown locking layer and precise control over the entire fabrication process, a team of researchers in the US (NIST, University of Maryland) reduced unintentional dopant movement while achieving high quality epitaxy in scanning tunneling microscope (STM)-patterned devices. They demonstrated the exponential scaling of the tunneling resistance on the tunnel gap as it is varied from 7 dimer rows to 16 dimer rows, the capability to reproducibly pattern devices with atomic precision and a donor-based fabrication process where atomic scale changes in the patterned tunnel gap result in the expected changes in the […]
The observation of photon-assisted tunneling signatures in Majorana wires
Phys.org May 12, 2020 An International team of researchers (Denmark, USA – UC Santa Barbara, MIT, Caltech, Sweden) has developed a scheme for preparation, manipulation, and read out of Majorana zero modes in semiconducting wires with mesoscopic superconducting islands. They outline a sequence of milestones interpolating between zero-mode detection and quantum computing that includes (1) detection of fusion rules for non-Abelian anyons using either proximal charge sensors or pumped current, (2) validation of a prototype topological qubit, and (3) demonstration of non-Abelian statistics by braiding in a branched geometry. The pre-braiding experiments can be adapted to other manipulation and read […]
New quantum switch turns metals into insulators
EurekAlert February 3, 2020 In a Mott insulator free flow of electrons is facilitated by reducing the strength of the repulsive interaction between electrons, or by changing the number of electrons. An international team of researchers (Canada, Germany, Switzerland, USA – Lawrence Berkeley National Laboratory, Ohio State University, Oak Ridge National Laboratory, South Korea) explored a way to alter the very quantum nature of the material to enable a metal-insulator transition to occur. They found that in Sr2IrO4 coupling the spin to the orbital angular momentum slows the electrons down to such an extent that they become sensitive to one […]
Engineers using soundwaves to search through big data with more stability and ease
Phys.org September 19, 2019 Using three aluminum rods, enough epoxy to connect them and some rubber bands for elasticity researchers at the University of Arizona have demonstrated the possibility for acoustic waves in a classical environment to do the work of quantum information processing without the time limitations and fragility. They sent a wave of sound vibrations down the rods, then monitored two degrees of freedom of the waves: what direction the waves moved down the rods and how the rods moved in relation to one another. To excite the system into a nonseparable state, they identified a frequency at […]
‘Valley states’ in this super-thin material could potentially be used for quantum computing
Phys.org September 23, 2019 Past research has shown that applying a magnetic field can shift the energy of the valleys in opposite directions, lowering the energy of one valley to make it “deeper” and more attractive to electrons, while raising the energy of the other valley to make it “shallower,” A team of researchers in the US (SUNY Buffalo, University of Nebraska) showed that the shift in the energy of the two valleys can be enlarged by two orders of magnitude if we place a thin layer of magnetic europium sulfide under the tungsten disulfide. After that when they applied […]
Physicists ‘teleport’ logic operation between separated ions
Science Daily May 30, 2019 Teleportation of quantum data has been demonstrated previously with ions and a variety of other quantum systems. Now a team of researchers in the US (NIST, University of Colorado) teleported a quantum controlled-NOT (CNOT) logic operation, or logic gate, between two beryllium ion qubits located more than 340 micrometers apart in separate zones of an ion trap, a distance that rules out any substantial direct interaction. A “messenger” pair of entangled magnesium ions is used to transfer information between the beryllium ions (infographic ). They found that its teleported CNOT process entangled the two magnesium ions […]
An Optimist’s View of the 4 Challenges to Quantum Computing
IEEE Spectrum March 22, 2019 According to some experts quantum computing will never materialize as it will require control over an exponentially large number of quantum states, and that this amount of control is too difficult to achieve. According to Intel there are four key challenges that could keep quantum computing from becoming a reality – Qubit Quality, Error Correction, Qubit Control, Too Many Wires. Researches at Intel are working to tackle each of these challenges. But if solved, we could create a commercially relevant quantum computer in about 10-12 years… read more.
Quantum strangeness gives rise to new electronics
Eurekalert February 11, 2019 An international team of researchers (USA – Arizona State University, Japan, China, UK) explored the charge transport properties through the molecules. They demonstrated that quantum interference can be precisely modulated in two different configurations of the molecule, known as Para and Meta. It turns out that quantum interference effects can cause substantial variation in the conductance properties of molecule-scale devices. By controlling the quantum interference, the group showed that electrical conductance of a single molecule can be fine-tuned over two orders of magnitude. The research shows that the field of molecular electronics is open to a […]