texas a&m physicists are devising computer codes and prototypes of quantum computers which may be the next generation of computers an ordinary computer may seem very sophisticated but in fact it is only programmed to gobble large series of ones and zeros and spit out other large series of ones and zeros it is that simple because a combination of zeros and ones can make up all possible numbers all possible operations on these numbers – for example addition subtraction or division – are also simple in principle because they rely on logical rules of combinations of zeros and ones this basic structure of zeros and ones is limited however because only one number is processed at a time the most dramatic example that has been tackled by computer scientists so far is factorization says suhail zubairy visiting professor of physics at texas a&m you have a large number and you want to factorize it if you take a thousand-digit number on the fastest computer today factorizing it would take a few billion years factoring can be important to encryption of numbers which keeps your credit card number secret when making computer-transacted purchases in order to avoid infinitely long calculations and further optimize current computers scientists have started devising a new way to simultaneously process many numbers this is possible for a quantum computer in an ordinary computer every number is represented by a series of bits with each bit taking the value zero or one zero or one means that a switch is set to off or on respectively one bit makes zero or one two bits make the numbers zero one two or three (00 01 10 or 11) three bits make one of the numbers zero to seven (000 001 010 011 100 101 110 111) and so on in a quantum computer each bit which is now called a qubit or quantum bit can be simultaneously zero and one this strange property of quantum physics permits three qubits to hold all of the numbers zero through seven at the same time the bottom line: in an operating quantum computer there is both zero and one in each qubit while there is either zero or one in each bit of an ordinary computer for instance a calculation using three qubits might involve all of the numbers zero through seven simultaneously but at the end of the calculation i get only one number out as with a usual computer says david church professor of physics at texas a&m the one number i get could be random anywhere between zero and seven which does not seem to help me at all which number is the right answer to the calculation this apparent paradox is solved by the way calculation is performed called quantum interference when the final result is read the single correct answer is very probable not random in a quantum computer zero or one might be associated with the internal energies of an ion – a charged atom – which act as a qubit the ion can have low internal energy – called zero – or higher internal energy – called one – or exist in an intermediate stage the intermediate stage corresponds to a qubit that is both zero and one laser pulses are applied to each ion to put it in the intermediate stage church says by studying the light emitted by these ions it is possible to derive the actual number they represent in the case of three bits three ions would hold the numbers zero through seven and each ion would interact separately with the laser light he says the study of quantum computing using singly charged ions is being pursued at the national institute for standards and technology in boulder colo at los alamos national laboratory in los alamos nm and in europe church has been collaborating with the lawrence livermore national laboratory in livermore calif to study the possibility of quantum computing using highly charged – instead of singly charged – ions we have used the facilities of livermore laboratory to confine and cool highly charged ions church says it turns out that these ions have many internal energy states that are accessible to lasers simulations also show that when sufficiently cooled these ions form regular arrays church says that work on quantum computing is just lifting off the ground and is highly interdisciplinary involving at once physicists chemists computer scientists engineers and mathematicians he is currently teaching a course in quantum computing along with walter daugherity senior lecturer of computer science at texas a&m contact: david a church (979) 845-2841 or church@physicstamuedu aggiedaily office of university relations texas a&m university (979) 845-4641