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I still don't quite understand: "The method is 'analogue' in the sense that it is not like Shor's algorithm, which is programmable in a quantum computer follow

I still don't quite understand: "The method is 'analogue' in the sense that it is not like Shor's algorithm, which is programmable in a quantum computer following the gate model. Instead, it is the measurement of a carefully set quantum system that provides the answer." Isn't the gate model _also_ a carefully set quantum system, the measurement of which provides the answer? Can someone shed some light on this please?

j1vms 10y ago
As a rough way to understand this, take a look at the difference in operation between an analog computer [0] and a digital computer. One of the main differences is that an analog computer does not achieve a given "operation" (e.g. integration of an input function) via a discrete heurestic (i.e. by executing the calculation in steps using say numerical integration), but rather the analog computer embodies the operation itself via its underlying physics. Essentially, these researchers have proposed a way to tackle integer factorization by creating a quantum system that embodies the calculation itself, rather than performing discrete steps on an input to find its factors as one would via, say, Shor's Algorithm on a "general-purpose" quantum computer. As is mentioned in GP post's link, this is potentially a significant result in both pure math (quantum number theory) and applied cryptography. [0] https://en.wikipedia.org/wiki/Analog_computer https://en.wikipedia.org/wiki/Analog_computer
WhitneyLand 10y ago
Imagine creating a device to keep track of time. A couple of ways to do this are: 1). Use a programmable computer to write code 2). Place a gnomon on a flat plate to make a sundial The first way is the gate model, it's algorithmic, like Shor's algorithm. The second way is analog. There is no algorithm. The solution consists of simply measuring a shadow.

j1vms 10y ago

As a rough way to understand this, take a look at the difference in operation between an analog computer [0] and a digital computer. One of the main differences is that an analog computer does not achieve a given "operation" (e.g. integration of an input function) via a discrete heurestic (i.e. by executing the calculation in steps using say numerical integration), but rather the analog computer embodies the operation itself via its underlying physics. Essentially, these researchers have proposed a way to tackle integer factorization by creating a quantum system that embodies the calculation itself, rather than performing discrete steps on an input to find its factors as one would via, say, Shor's Algorithm on a "general-purpose" quantum computer. As is mentioned in GP post's link, this is potentially a significant result in both pure math (quantum number theory) and applied cryptography. [0] https://en.wikipedia.org/wiki/Analog_computer https://en.wikipedia.org/wiki/Analog_computer

WhitneyLand 10y ago

Imagine creating a device to keep track of time. A couple of ways to do this are: 1). Use a programmable computer to write code 2). Place a gnomon on a flat plate to make a sundial The first way is the gate model, it's algorithmic, like Shor's algorithm. The second way is analog. There is no algorithm. The solution consists of simply measuring a shadow.