6 ms·

Intel's 49-Qubit Chip Shoots for Quantum Supremacy

54 points by amaks 9y ago

Tempest1981 9y ago
What makes one quantum computer superior to another? Not number of qubits, I guess? IBM has a 50-qubit machine.
- ajdlinux 9y ago
  IBM talks about a metric called "quantum volume" that combines number of qubits with error rate to summarise useful computing performance. See https://dal.objectstorage.open.softlayer.com/v1/AUTH_039c3bf6e6e54d76b8e66152e2f87877/community-documents/quatnum-volumehp08co1vbo0cc8fr.pdf https://dal.objectstorage.open.softlayer.com/v1/AUTH_039c3bf... (disclosure: IBMer, but very different area)
- btian 9y ago
  Same as classical computers, what makes Intel i7 superior to AMD Ryzen 7? One that can perform a computation task fastest with least energy would clearly be superior to another.
edcarter 9y ago
Is it vulnerable to meltdown?
- macawfish 9y ago
  maybe if you run out of liquid helium ;)
- deepnotderp 9y ago
  No.
- ganeshkrishnan 9y ago
  Maybe if it was running real world applications with system and user space. Right now these all run prototype code
wopwops 9y ago
Breaking Bitcoin With a Quantum Computer http://fortune.com/2018/01/06/breaking-bitcoin-cybersaturday/ http://fortune.com/2018/01/06/breaking-bitcoin-cybersaturday... Quantum Resistant Ledger https://theqrl.org/ https://theqrl.org/
- lostmsu 9y ago
  It is unknown if BQP >= NP or NP-complete
  - tromp 9y ago
    NP-completeness is a property of problems, while BQP is a complexity class (set of problems). If any NP-complete problem is in BQP, then NP is a subset of BQP. But it's not even known whether BQP > P, so we could have P = BQP < NP.
Strilanc 9y ago
Did they give any numbers on the quality of the qubits? For example, IBM's 20 qubit chip has 2-qubit operations with error rates on the order of 5% [1] (some pairs of qubits are better, some are worse). Quantum supremacy experiments require thousands of operations (tens of layers of parallel operations). Qubits with even a 1% error rate per operation just won't cut it. 1: https://youtu.be/T-8uuq7Izl8?t=26m58s https://youtu.be/T-8uuq7Izl8?t=26m58s "Experimental quantum computing at IBM" [26:58] (Disclosure: I work on Google's quantum team.)
- vtomole 9y ago
  > Did they give any numbers on the quality of the qubits? No they didn't. I've also had problems finding the benchmarks for their 17 qubit processor. I would appreciate if someone could link them to me.
wejick 9y ago
What is it means for humanity?
- googletazer 9y ago
  Better drugs/more complex medicines should be possible. Chemical interactions are hard to do on classical computers (operating on 5D+ arrays), true quantum computers should be able to help with those computations.
  - wejick 9y ago
    Do you have easy material for me to understand how quantum computing enables that kind of things? And does it use clasic numerical method computing or using different kind of mathematical approach? Actually I'm not sure whether my question makes sense or not
    - dilippkumar 9y ago
      I enjoyed reading this paper: https://arxiv.org/pdf/0708.0261.pdf https://arxiv.org/pdf/0708.0261.pdf
volkadav 9y ago
I guess taking every branch by default avoids the specter of branch prediction vulnerabilities? (This is me failing my saving throw vs urge to make terrible nerd jokes.)
krisives 9y ago
I assume these are massive like D-Wave's systems? https://youtu.be/60OkanvToFI?t=392 https://youtu.be/60OkanvToFI?t=392

54 points by amaks 9y ago

Tempest1981 9y ago

What makes one quantum computer superior to another? Not number of qubits, I guess? IBM has a 50-qubit machine.

ajdlinux 9y ago
IBM talks about a metric called "quantum volume" that combines number of qubits with error rate to summarise useful computing performance. See https://dal.objectstorage.open.softlayer.com/v1/AUTH_039c3bf6e6e54d76b8e66152e2f87877/community-documents/quatnum-volumehp08co1vbo0cc8fr.pdf https://dal.objectstorage.open.softlayer.com/v1/AUTH_039c3bf... (disclosure: IBMer, but very different area)
btian 9y ago
Same as classical computers, what makes Intel i7 superior to AMD Ryzen 7? One that can perform a computation task fastest with least energy would clearly be superior to another.

edcarter 9y ago

Is it vulnerable to meltdown?

macawfish 9y ago
maybe if you run out of liquid helium ;)
deepnotderp 9y ago
No.
ganeshkrishnan 9y ago
Maybe if it was running real world applications with system and user space. Right now these all run prototype code

wopwops 9y ago

Breaking Bitcoin With a Quantum Computer http://fortune.com/2018/01/06/breaking-bitcoin-cybersaturday/ http://fortune.com/2018/01/06/breaking-bitcoin-cybersaturday... Quantum Resistant Ledger https://theqrl.org/ https://theqrl.org/

lostmsu 9y ago
It is unknown if BQP >= NP or NP-complete
- tromp 9y ago
  NP-completeness is a property of problems, while BQP is a complexity class (set of problems). If any NP-complete problem is in BQP, then NP is a subset of BQP. But it's not even known whether BQP > P, so we could have P = BQP < NP.

Strilanc 9y ago

Did they give any numbers on the quality of the qubits? For example, IBM's 20 qubit chip has 2-qubit operations with error rates on the order of 5% [1] (some pairs of qubits are better, some are worse). Quantum supremacy experiments require thousands of operations (tens of layers of parallel operations). Qubits with even a 1% error rate per operation just won't cut it. 1: https://youtu.be/T-8uuq7Izl8?t=26m58s https://youtu.be/T-8uuq7Izl8?t=26m58s "Experimental quantum computing at IBM" [26:58] (Disclosure: I work on Google's quantum team.)

vtomole 9y ago
> Did they give any numbers on the quality of the qubits? No they didn't. I've also had problems finding the benchmarks for their 17 qubit processor. I would appreciate if someone could link them to me.

wejick 9y ago

What is it means for humanity?

googletazer 9y ago
Better drugs/more complex medicines should be possible. Chemical interactions are hard to do on classical computers (operating on 5D+ arrays), true quantum computers should be able to help with those computations.
- wejick 9y ago
  Do you have easy material for me to understand how quantum computing enables that kind of things? And does it use clasic numerical method computing or using different kind of mathematical approach? Actually I'm not sure whether my question makes sense or not
  - dilippkumar 9y ago
    I enjoyed reading this paper: https://arxiv.org/pdf/0708.0261.pdf https://arxiv.org/pdf/0708.0261.pdf

volkadav 9y ago

I guess taking every branch by default avoids the specter of branch prediction vulnerabilities? (This is me failing my saving throw vs urge to make terrible nerd jokes.)

krisives 9y ago

I assume these are massive like D-Wave's systems? https://youtu.be/60OkanvToFI?t=392 https://youtu.be/60OkanvToFI?t=392